Monday, July 25, 2022



The above remains my favorite hex type, though I do need to spend some more quality time around the Rockies to make sure. As I write this, I find myself once again in the great North American rainforest; this time in the western reaches of North Carolina, just on the far side of the Smoky Mountains where the Blue Ridge and Piedmont blend. 

I'm sitting on a deck a good 25 feet above the forest floor, and the trees within arm's reach stretch another 30 feet or more still. It's raining but that rain has yet to filter through the canopy. It's cool and green and good.


It is, as surprising to me as anyone else, the tenth anniversary of the blog, the illustrious Aluminum Anniversary. There's likely a time when I would have spun that into Something Relatable, maybe pulling out that merchant route calculator or what-have-you, but today is not that day. It hasn't been that day for quite a while - you may note that my plan to get through the backlog of unpublished posts here did not get out of it's own way, and we managed to miss the entirety of 2021. I was close to missing this minor milestone, in fact, but while packing for the trip I suddenly realized it was time for a Useless Summer Post - so let's go for whatever place on the podium the aluminum medal stands:

This was more than anything else a way for me to talk to myself with another voice, a luxury and a decadence, which has evidently lost its luster. I considered fading away, but will instead flicker out; spitting out the the grit of unpublished thoughts as it's become clear I'm not interested in enpearling them. Their irritation is more impediment than inspiration now.

Thanks to those that read, thanks to those that commented, and thanks to those that linked. I really did and do appreciate it.

Monday, May 4, 2020

ACKS Blackmarsh (4) - Viz

Good day to you, my most loyal of subscribers who have yet to delete their ties to this humble blog in a huff due to a severe shortage of content! While I cannot call this a comeback, I can call it at least a rolling over in one's sleep. My archive of unfinished, unpublished content is a wide field of weeds I have yet to pluck, place in the first cup I can reach in the counter and present to you as a doe-eyed child presents the first dandelion of spring to his or her mother. 

Behold, the first, tallest weed:

In the Smoking Bay lives a wizard, on a mountain that once fell from the sky.

It's rich in 'viz' - the Blackmarsh setting's version of "magic in physical form". Viz is vaguely defined, to whit it "could be a flask of pure spring water, a newly bloomed flower, or an iridescent rock". It's a thing that is another thing - 'viz' is a substance that takes on the characteristics of another object.

Much like other things, you know it when you see it. From my reading of Blackmarsh, 'viz' is something that's constantly renewing in the environment - there's ash trees in the Greywoods whose seeds contain viz.

It's like if "abiotic oil" was a real thing - here's this source of power just leaching into the world that just needs to be collected.

The Value of Viz

The two things that viz gives you is the ability to cast spells without wiping it from memory, one "viz" used per spell level, and it's worth 100GP towards magical item creation.

I'd mentioned earlier that one could probably treat viz and Dwimmermount's azoth as the same thing.

Turns out that's pretty darn easy.

Dwimmermount (ACKS), pg 360 - refined azoth is valued at 100 GP per ounce. Note the descriptors of what viz could be above - poetic, yes, but, also very much possibly things that could weigh an ounce.

So it could be deduced that some process in Blackmarsh is exuding refined azoth into or as everyday objects, including plant life and vermin. That's...kinda worrisome, really.

The expanded capabilities of refined azoth from various sources:
  • The GP value of refined azoth (100GP/ounce) can substitute for equivalent value for:
    • Some or all of the base cost of magical research
    • Some or all the special components required to create a magic item or perform a ritual spell
    • Some or all of the precious materials used to create a magic item, perform a ritual spell, create a construct, or grant undeath
  • If consumed (literally) the  spellcaster regains the ability to cast a spell of a level previously expended - one spell level per ounce.
  • Substitute the full base cost of alchemical transformation ( crossbreeding, creation of brand new lifeforms, or gaining immortality as detailed in Dwimmermount pg 399)
From Dwimmermount, it has a number of side effects; it's combustible for one, acting as double-strength flaming oil.

Touching or consuming refined azoth causes a save; if failed, a set of tables determines effects that are a mix of helpful and baleful.

But, as things go, just because it's potentially harmful doesn't mean people won't seek it out - we don't need a fantasy world to prove that. There's a bit of a 'gold rush' theme tied to viz, but nothing terribly defined, as far as amounts or ease of finding. 

We can make a guess about the relative value of viz.

A load of semiprecious stones weighs a stone, and averages 1,000GP in value. Precious gems are the same weight, and 3000GP in value.

A stone is about 10 pounds. There's 16 ounces in a pound, so there's ~160 ounces in a stone, and therefore a "load" of viz weighs a stone and is worth ~16,000GP at face value.

Sources of Viz

Let's assay the landscape:

The Greywoods: Several hexes - "grey ash" trees drop seeds that are a "potent source" of viz.

Hex 0105: the ruins of Daur Anthar, there was a vein of metal rich in viz.

Hex 0217: Oldan Hold; established as a base for dwarves from Bolzak seeking viz; the lord of the keep, Mazardan, heads an adventuring company seeking viz. In fact, the dwarven Lord Mazardan will pay 200 GP per viz brought to him; that's "over value" for it's use.

If we take the face value of 100GP, that's a 200% markup. We can have a maximum demand modifier of +4, I believe, modifying a 4d4 roll for market price - that's a maximum roll of 20 on 4d4+4, to get to 200%.

Clearly, Oldan Hold wants viz, enough that they're willing to pay maximum adjusted market price for it.

Hex 0616: Mages of the Bright Empire once harvested viz from a half-mile long, 50' deep gorge.

Hex 0804: Stardell Falls, a 40 foot waterfall, is a "rich source" of viz.

Hex 0913: Castle Blackmarsh, survived for a time on the traffic of folks seeking viz. Has an elite association of adventurers called "the Viz Club".

Hex 1112: Bright Empire's last treasure ships from Blackmarsh; contains crates of viz.

Hex 1309: The Mountain That Fell; "incredibly rich" in viz; guarded by a high level mage.

Hex 2114: Mermaids collect shells for a pool in the center of the island; they turn into viz during the full moon (4d6 of them).

Hex 2401: A giant ant lair; 1 in 20 eggs are viz.

Hex 2410: Large pillars with compartments "where viz can be inserted".

That's a lot of different things. I'm interested in what I can pull out of this and define. (and yes, I realize I'm missing the point of not defining it, much like the robot who knows the chemical composition of the rose but will never know love, but this is my fun-time, let me go)

The Mountain that Fell a good place to start. 

Presume the Wizard of the Isle is a 14th level mage. (Dwimmermount includes a progression table for ACKS up to 18th, but we'll stick with 14 for now) His actual HD may be higher, he's probably transmogrified himself, since he's been around for centuries. It may be construed he's unlocked some form of immortality  as per Dwimmermount, pg 408.

He has no domain or realm.

The realm he presumably could be running, however, is an empire of millions. 

The minimum assumed income for an empire; ACKS pg 230, is somewhere in the neighborhood of 385,000GP per month. For completeness, that number jives with a 14th level character's Monthly Henchmen Wages (350K).

His expenses may technically be lower, as he's not providing for a population, but that could be easily subsumed into whatever measures he's taken and must maintain to guard the island itself. That golem probably doesn't come cheap.

Since the mountain is "incredibly rich" in viz, the Wizard is presumably actively doing wizardly things, one could posit that his "income" is gained via the procurement of viz. Since he's an immortal wizard on an island that exudes magic, I'm going to take a wild leap and say he probably doesn't spend money on mundane things, maybe, or fancy clothes, or anything that isn't furthering his research or protecting his research from others. I honestly don't think this guy would have apprentices, he probably has a small company of artificial creatures doing the extraneous work.

I'll continue, then, computing this base 385K of income as if it's all coming to him in viz.

Base division means, then, he's pulling 3,850 ounces, or 240 pounds (24 stone) of viz out of the mountain each month.

He can't spend that much in a month, though - not on the things that viz can be spent on.

The most expensive things our Wizard can do, on a day-to-day basis, is creating constructs, crossbreeds, or doing necromancies. For per-month output, nothing beats max-value construct creation, at something like 27.5K per month in created value. We can take the Abstract Magical Research rules and figure that this wizard only fails on a roll of 2+ (some special HFH class ability, can't recall which), invert the 1.05x multipler for cost, and easily state that:

The Wizard of the Isle takes in 27.5Kgp of Azoth per month, and converts that to abstract magical research value totalling 26.2Kgp per month, in items, constructs, or just plain library value, as needed.

Mining for Viz

We know how much viz is worth -  - how much viz do we pull out of that space?

Let's take the Axioms mining rules as an example, and think of it like a gem mine.

We know 140 carats is about an ounce, and by density a diamond of that size is about three-quarters a cubic inch in volume. That's not a bad size for what we see above in the descriptions for viz sources - seeds, shells. Giant Ant eggs might be up to 8 lbs, but maybe it's just a portion of the egg.

Value-wise, it's way off though; a 140ct diamond is probably damn near invaluable - in the real world a 163 carat diamond went for about $34 million at auction. So, we'll table that for now, and we'll look instead at results.

Each bit of viz is 100gp, and we need 275 bits per month to fuel research. That's about 17 pounds of viz at an ounce (140 carats) per bit, and as such we need to dig out 38,080 carats per month.

That's a very big gem mine. Like, wizard-did-it big. Fortunately for us a wizard has indeed done it.

We need to net 16 times the yearly profit of an ornamental gem mine per month. If 200 work gangs produce 2,400 carats in a year, that's 12 carats per gang per year - or, 1 carat per gang per month.

That's 38,080 work gangs, or 190,400 people, digging out 11.4 million cubic feet of material per month - a cube of material 225 foot on a side, or a small mound about 80 ft tall and 160 ft in width.

Clearly inexplicable, cause as the Dungeon Master says,


Well, so, the Wizard did it, and if we've got a wizard with a teleporting construct that guards the surface of the mountain, what the heck you think he's been up to underneath? That's right - horrible spiky bladed relentless digging machines.

From D@W:C we know that monstrous workers multiply their labor rate by their normal load divided by 5. 

Giant Crabs seem diggy, have a load of 210; divided by 5 that's 42, that's 4,533 giant crab constructs.  (190,400 lazy humans divided by 42)

That's ridiculous and terrible, but is it the best we can do? Of course not.

Purple Worms, the very essence of "dig", clock in at a load of 320; that's a divisor of 64 or 2,975 purple worm looking constructs roiling up to the lab to barf out little bits of viz every couple days.

That's pretty ridiculous and quite terrible, but I'mma stop you right there, and tell you who has the greatest normal load of ALL TIME.


(greatest load...sperm whale... just, you know. Enjoy that.)

Boasting a 2400st normal load, that's a divisor of 480, and so 397 sperm whale constructs constantly churning the nethers of the mountain, surfacing in some infinite dance loop of choreographed terror to spit collected viz out of their blowholes and into some sort of collection apparatus.

That gold construct's not there for defense. He's there to warn you that you're hilariously out of your league.

Wizards cheat though...

The best way to run a high level wizard is to assume that the wizard has a copy of the rulebooks of the game she lives in.

The best CCF in the L&E monster creation rules is 0.430, for the Coleopteran/Beetle body form, with a set BME of 1.62. Weight is (HD*10)^BME, and so CCF*(HD*10)^BME)/5 is the formula for figuring out the divisor - or, 0.430*((HD*10)^1.62)/5.

That simplifies to 16*HD, assuming I remember how to math. If we want 397 beetles with a 480 divisor, that's a 30 HD beetle. At 30HD the beetle form is 10,300 lbs, merely gigantic instead of colossal, costing with at least one "*" ability 65,000 gp.

Technically it's a bigger construct in HD than a 14th level mage can make, but, only by 2HD, I feel like there was maybe a proficiency in a later book to give a bit of a level bump, and if not, there should be. Or, again, the referenced Wizard already exceeded mortal limitations.

400ish gigantic beetle-looking constructs. roiling around in that mountain. My guess is that they don't even remove the material, they just fill it in behind themselves, and there's just something that makes little tiny bits of 'viz' spontaneously generate that they store in their giant midguts until they emerge engorged and ready to vomit it out.

Alternatively, assume there's some time period between the digging and the filling, and at any given point there's 11.4 million cubic feet of tunnel - let's say these guys make 20x20 tunnels, so that's...28,560 linear feet of random tunnels PCs could blunder into and explore for a little bit before they are summarily chewed up or crushed by the next gigantic beetle construct to cross their path.

Anyway, it took the Wizard about 78 years to make all those beetles, assuming he did it by himself, using the abstract rules. It's left as an exercise for the reader to figure out how to shorten that. I'd suggest a construct-making construct. Or, actually, a construct-making construct-making construct?

Monday, April 29, 2019

A Number of Irelands

In looking at various ways to abstract the game down to its fundamentals, one starts looking at things outside the rules a bit - or, things that start to intrude on the fiction of a game world.

In a system where building strongholds and ruling lands is a thing, one might step back and ask how best to enable it - what ought one do to provide the opportunity?

The guidelines say something like this, when talking about the status of a hex as being civilized, borderlands, or wilderness:

  • Within 50 miles of a large town, it is civilized.
  • Within 25 miles of the civilized border, it is borderlands.
  • Else, it's wilderness.
Now - some of the above relies a bit on the assumptions that settlement patterns and the general traffic of "civilization" tend to tamp down on the occurrence of wandering monsters - the bellwether of hex status, and makes no nods towards the realities of terrain, etc. We will assume for the moment this works as stated.

Assume a spherical cow domain.

and there's the map. Blue is our little center large town. The green bits then are the 50 mile radius around that town that is civilized by default; then the yellow is our borderlands, and the red our wilderness, as we have to end it somewhere, and another 25 miles out is fine.

Our landmass is the platonic ideal of such things for campaign purposes - a disc 200 miles wide. If we look at that through a lens of high occupancy, if not maximum:

Area (sq mi)6m HexesFam/HexPossible Families
Civilized Green7854252500126000
Borderland Yellow981831520063000
Wild Red1374444110044100

You can see that the consecutive areas of C/B/W embiggen, because geometry, and there's about twice as much wilderness as there is civilized area. 

233K families is a principality. We're looking at a Class II city there in the middle, 4 or 5 Class IV large towns (which would kinda bulge out the civilized area, but we'll deal with that later), then maybe 12-15 Class V's scattered at the edge of the borderlands.

More realistically, the totals may be more like one half or three quarters those levels; perhaps a Class III city as the centermark, with the outlying cities barely reaching IV status.

The demographics of either of those aren't horrific - you're looking at a 10th to 12th level NPC at the top. A party that's focused on their goals can knock that over and take control - or at least gain enough for a credible shot at independence. Or, if we're setup already with a set of independent smaller domains, perhaps conquering one and uniting the island from there is on the menu.

Out in the interwebs there's the idea of measuring things in the number of Libraries of Congress, as far as data goes, or the number of Rhode Islands, in terms of area.

For this, however, we might state that for a campaign maybe all you need is the minimum of one Ireland... order to  have a compelling space for a set of would-be conquerors to operate in.

As I recall, Jack Vance's Lyonesse was near the size of Ireland - so - I find myself in proper company.

Sunday, October 28, 2018

Where the Shadow lies

Hey! I know, long time. Life, right?

Anyway - a quick hit:

Mordor and Mirkwood got the way they were because of the presence of Sauron.

Presume for the moment that an Sauron-like entity - or whatever, honestly - produces a 'sinkhole of evil' effect that extends for miles, probably based on its HD or whatever apparent power level you assign.

That effect is a negative modifier to the d12 encounter table roll.

You then extend your d12 encounter table for the region into the negatives - however far you need to go - so that you can resolve rolls like "-3" to, say, orcs. Or evil spiders. And that's what the party encounters more often until such time as the Shadow is resolved/eliminated/depowered.

This has two excellent consequences:

- Modifying the encounter tables also modifies the monster settlement patterns, as that also gives you lairs when generating an area, or Wandering Into War results.

- The Abstract Dungeon adventuring rules use a "d8+d12" roll for resolution - the same roll as a wandering encounter - and therefore using that same negative modifier makes dungeons within reach of the Shadow more dangerous.

So, if I were to flesh this out in the future, I'd do something like:

- Evil presence "pushes" a negative modifier out to a distance based on its HD and a distance comparable to what a PC of equivalent HD might rule - so Sauron can cover the land of Mordor based on the fact that a ??HD PC could rule an empire.

- That presence pushes out over a time period based off the mercenary recruitment charts, maybe.

- The negatives increase closer to the source, again based on something derived from domain control.

- Abstract dungeons/lairs in the area inherit the negative modifier.

- When defeated, the modifiers reverse themselves on the same schedule, though any existing lairs remain. I expect I'd want to figure out how to reduce the negative modifiers on dungeons/lairs at a slower rate.

I'd have to cogitate more on how to manage the encounter rolls while lairs/dungeons that remain shadowed still exist in the area.

Spiders of Mirkwood

John Howe LOTR is best LOTR.

Friday, July 27, 2018

Campaign End

Freshly back from the wilds of Minnesota, I realized I even missed my useless summer post this year!

In other news, my campaign ended.

It ended ...probably as well as it could have. The overboisterous fighter finally talked himself into a showdown with local, more established powers and earned a siege.

The fighter had an ill-advised scheme to pretend to surrender, buying time for the undercautious voudon witch to execute on a summoning he ought not have. He didn't have enough troops to oppose the siege. The opposing ceremonialist and the leadership of the brigand crew besieging the joint whipped their troops into a charge around the daemon (the witch having a bit of a tactical breakdown trying to stop all this, as he was the only force on the battlefield at this point) to hit the witch and his pile of assistants to break concentration and retreat.

That succeeded. Due to positioning, the witch and three of his assistants were able to flee with the remaining forces in the fortress (the fort-temple from N1: Reptile God) and hide out in the sub-sub-basement while the daemon rampaged around for a bit and finally disappeared.

Those villagers and militia were...unimpressed with the effort the witch put into their defense, and he and his assistants were forced to take a little boat into the underground river and head into the unknown darkness. His fourth assistant had previously fled the battle while everyone was above-ground - probably off to the underground complex once owned by the necromancer Nuromen to do who-knows-what.

The druidic witch, her wolves, and giant hawk quit the field once the summoning was done and the extent of the desperation revealed itself. The assassin and his two followers also escaped.

The fighter died on the battlefield, overplaying his hand.

So what happened?

One thing, mainly: my desire to introduce a bit of domain play early - with the party inheriting nominal control of the little town at about 2nd level via the resolution of the N1: Reptile God hook - took a few of them off-task.

By off-task, I mean doing what parties of 1st-5th should be doing - putzing around their local area, completing achievable dungeon plunders, getting gold.

Rather, the little fledgling domain took focus - and that's not sitting around administering it - they spent a good deal of time traveling the region and recruiting peasants to live in their little corner of the world, with only a few random encounters to provide character advancement.

Worse, the fighter, in a fit of espirit de corps, let them all be their own landowners, which basically eliminated any domain income.

The final part was looking for threats to the domain specifically, finding those threats, and in this particular case, pissing off those threats.

Without the income from adventuring, they couldn't counter a lot of this.

I didn't really provide anything more than cursory advice; so, I was no help - nor should I have been, really. Gotta have bite for your bark, and there were enough things to do that weren't what they did.

Anyway. Gaming continues, this time as a player - one of my players was one of our group's usual DMs, and he's taking over for a spell.

Here, eventually, I'll get back to blogging with largely pointless expositions and poorly pasted tables of mechanics what-don't-need-fixin', which will be nice, for me at least.

You, maybe not so much. :P

Friday, December 22, 2017

The world is yours.

(had to retitle the post, can't believe I missed a chance at a Motorhead reference?)

For Christmas, I give you the world:

or an approximation on 96 mile (approximately) hexes.

I've gotten my hex map project to a point where I'm using it in-game; and rather than go down my next rabbit-hole of figuring out the effects of population on forest coverage (and thereby illustrating the concentrations of population on the map itself, vs trackless forest), I thought I'd take a stab at replacing another bit of my toolchain with my own code - the one that takes the spherical grid and aligns it to a classic 'flat' hex map grid.

That's the initial result.

Few things to note:

  • The grey-blue or whatever was marking out 96 mile hexes fully within the 0-200m bathymetry of the ocean. Those 'lines' are where the code tripped on the fact some of the shapefiles are broken up into individual shapes.
  • The triangular inclusions into the map is where pentagons exist on the grid; the pentagons are what allow it to 'wrap' unto a sphere. My code is currently ignoring them, so bits of the landmasses, like where western Europe breaks off of Asia, are rotated off to one side or another. It's going to be an interesting problem to stitch those back together without human intervention, while keeping the same side of all the hexes 'north'.
But, not at all bad for an initial stab. Once I solve the 'split' thing, I'll come back through and figure out how to 'zoom in' on individual hexes rather than regenerate the grid at the wanted scale.

Hope ya'll are having a good holiday.

Thursday, February 2, 2017

The Lightly Fantastic

Surprisingly, I'm prepping for a game.

As things go, then, I've been thinking about "stuff", and stuff tends to go in all directions.

This one is somewhat philosophical, and mostly stems from my wife being a biologist, who has occassionally taken umbrage with D&D's more ... practical classification metrics.

There is the concept of what's 'natural' and what's not - the difference between a hummingbird and a dragon, let's say. One of those is clearly mythical, and due to various characteristics, unless we demote dragons to  dinosaurs, eliminating the supernatural, they are not "beasts" in the usual term.

ACKS, as well as the maternal d20, classified various creatures into clean buckets in order to delineate what works on what, more or less. Some of these are more defined than others - undead is pretty clear, whereas vermin seems to be a catch-all for various non-magical invertebrates.

I'm mostly cogitating on the definition of "animal" versus Fantastic Creature.

There are several technical subcategories that immediately jump out. Anything sentient is rightly marked.

But what about griffons, let's say?

It's clearly a mix of odd pieces. There are, generally, several arguments against it being able to operate successfully in the real world.

But is it really fantastic?

At what point is there no difference between "evolved that way" and "a wizard did it"? Especially in an assumed world where wizards can indeed "do it"? As a sharper point than I  usually make on this blog, I expect I could walk down the street and find someone who, if I'd point out a robin, would tell me that it sprang from nothingness at the time of Creation, or some variation thereof.

Robins are marginally fantastic, yet a double-digit percentage of the population will argue that their origin is even more fantastic as that assumed for the griffon.

Added to that, then, is my SRTM map experimentation is for many purposes "solved", and I'm assembling a toolchain that will allow me to output hex maps of any* given section of the globe in proper** hex sizes with elevation and terrain data.

With that implies the real world, and real-world sorts of occurrences. There's no way humans would not have made every attempt at, and successfully accomplished, the domestication of things like hippogriffs and griffons. The news last year from the Ringling Bros. before their closure would have been just as likely to have been the decision to no longer use hippogriffs on their road show.

Add into that Lairs & Encounters (and Domains At War) allowing us to achieve a creature economy with regards to ownership, care, and training, thus enabling one to systemically manage the occurrence of the same in the campaign world.

But for the sheer cost, there's no reason a hippogriff or a griffon or some such wouldn't be found in the stables of the ranked members of society - especially those who display these creatures on their heraldry and such.

* some areas are 'unmappable' due to the construction of the spheroid, but those locations are centered in open ocean, and the ability to map near them is dependent on the defined hex size
** within a few square miles of area of the 768, 192, 96, 24, 6, and 1.5m hex sizes for my purposes, though there's many more options available

Anyway. With an eye towards finding what might work as a "real animal" without violating the basest of biological or physical assumptions, we can come into a new view of what's probably a creature that's only lightly fantastic.

Cutting out the sentient members, what do we get in the Fantastic Creature section?
  • Amphisbaena (L&E): Clearly out, as it has two heads.
  • Kraken (L&E): Would fall into the Giant/Prehistoric category, more naturally.
  • Yali (L&E): It's aligned Lawful - that, above all else, disqualifies it.
  • Basilisk: Turns people to literal stone. Out.
  • Cockatrice: The same.
  • Gorgon: Again, petrification.
  • Griffon: Mixed body shape, no supernatural abilities.
  • Hippogriff: As Griffon.
  • Hydra: Multiple heads and possible breath, so it's out.
  • Owl Bear: As Griffon.
  • Remorhaz: Supernatural heat - if it was intelligent, it may fit as an weird dragon type. Out. 
  • Rust Monster: This is a good one. Vermin which may be a better idea if one would assume the rusting ability is of more mundane origin.
  • Sea Serpent: Giant/Prehistoric.
  • Skittering Maw: I would argue that this body form would fall under Vermin.
  • Stirge: Completely normal, relatively speaking.
  • Wyvern: Technically a dragon in d20, but here? Giant/prehistoric at worst.
So, under this, we're left with:
  1. Fantastic Creatures
    1. Amphisbaena (L&E)
    2. Yali (L&E)
    3. Basilisk
    4. Cockatrice
    5. Gorgon
    6. Hydra
    7. Remorhaz
  2. Vermin
    1. Rust Monster (if rusting is "mundane")
    2. Skittering Maw
  3. "Animal/Giant Animal"
    1. Kraken (G)
    2. Griffon
    3. Hippogriff
    4. Owl Bear
    5. Sea Serpent (G)
    6. Stirge
    7. Wyvern (G?)
My own judgement aside, I think the main reason Hippogriffs and Griffons (...Wyverns?) are treated differently is because they are the "premium mounts" of the D&D world - owlbears are just good fun, and stirges are "trap  monsters". There's nothing truly fantastic about any of the five.

Given all of that, I'd rather categorize things as:
  1. Animals: what one would expect.
  2. Preternatural Animals: Giant, Prehistoric, Mixed type animals; up to Huge in defined size
The Huge limitation, which sets our upper bounds at about elephant size, is an attempt to cut out things like the sauropod dinosaurs, krakens, and such. Animals of such expanse that it seems improbable that a mundane human can interact with them in such a way that training can easily occur.

And, in order to see how this will work out in live play against a known antagonist with regards to these sorts of things (i.e.; my loving and loved wife, reprising her favored role as a druid, or how she styles things, Beastmaster of the Apocalypse)

Beast Friendship: ...taken a second time, the character gains a +2 to reaction rolls with, and may recruit as henchmen, creatures of the Preternatural Animal type of up to Huge in size.