A framework for creating animal companions

[Drakli]

Please clue me in, Paizo gurus!

There must a framework for designing animal companion species and establishing stats they should have at a level 4 or 7 advancement.

My only problem is, I don't know what it is.

Let's say that I want a hippo companion. I have the stats for a hippo from the Tome of Horrors. But until it actually exists in a Bestiary, I'd have to eyeball it based on another species.

Or if the bear animal companion doesn't match up with what I want in a bear. (I know this is an old road, but I still want a bear I don't have to be a halfling to ride. Lion and Tiger fanciers get large animal companions and they get stuff like rake and pounce too.)

Or if I want to use Vermin Heart and have a vermin companion... mind you, this isn't just a PC problem. If I want a villain or NPC like

Spoiler:

the crazy Beekeeper gnome,

I need to know how to make an animal companion to know how to make a vermin one.

... so yeah, part of this is wondering how animal companions are built the way they are so I can make one, and part of it is because I wonder why some animal companions are designed the way they are.

I would love for some future book, or web PDF or whatnot that tells me... here is how to design x animal into an animal companion. That would be extremely useful for people like me who get a little nervous with the idea of eyeballing it. Or at least, for someone to say "here is how we estimate it," please.

[underling]

Drakli wrote:

I need to know how to make an animal companion to know how to make a vermin one.

... so yeah, part of this is wondering how animal companions are built the way they are so I can make one, and part of it is because I wonder why some animal companions are designed the way they are.

I would love for some future book, or web PDF or whatnot that tells me... here is how to design x animal into an animal companion. That would be extremely useful for people like me who get a little nervous with the idea of eyeballing it. Or at least, for someone to say "here is how we estimate it," please.

Well, this is a little fast and loose, but here is what i was able to discern by reverse engineering the existing companions against their bestiary entries. These rules work for 90% of the existing companions, and deviations appear to be design decisions (altering rake for tigers, etc...)

1- at 1st level the animal is one size category smaller than the adult version. All attack dice are lowered via size rules (d8 becomes d6, d6 a d4, etc...) and stats are lowered based off the stat size change table located half way down this page.

2- If the animal moves from small to medium, or has weak stats, it upgrades at 4th level. IF it goes to large, or is especially tough (deinychous) it upgrades at 7th.

3- for a rare few animals (eagle, camel, horse) where no size change occurs, the animal gains +2 to str and con at 4th. This typically puts the animal at a net +2 over a vanilla version from the bestiary.

I used this myself for vermin, using large versions of the scorpion, centipede, spider, mantis and stag beetle. It seemed to work fine.

[Mok]

Also, in terms of statistics for the land based animal companions the stats break down on average as:

Str 12.27
Dex 15.85
Con 12.52
Int 1.88
Wis 12.39
Cha 6.79

And on average the total of all six stats equals 61.7

So staying somewhere around those medians should work.

The big challenge with vermin is that they are mindless, so directing it around with handle animal tricks is kind of hard.

For an animal companion vermin I'd give it an Int of 1 so it can function as a companion.

Another balancing factor that happens with Animal Companions is the hit points. In general if the companion gets some interesting enhancement, has lots of natural armor, or really good natural attacks then it's Constitution score tends to be lower to offset the advantages.

As an example, a dog is more durable (hit point wise) than most dinosaurs, or even bears, apes, etc.

Since vermin are usually getting poison attacks it's likely their Con is going to at best be a 12 for game balance reasons, and probably more like a 10.

If you are making a bee, something that can fly, then it's going to have to take a hit somewhere to make it fragile or weak in attacks as the flying is a great advantage.