
ohako |
Wow. That is just so much simpler than the route you need to take for your familiar to gain a familiar. My first reaction is to do 'Tom and Jerry', like a small cat and a dire rat. My second thought is to do 'falconer ahorse', where your horse companion gains a bird companion.
Your AC would need ranks in Handle Animal. How weird is that? In theory, such an animal could make itself perform a trick it didn't know. The mind boggles.

lemeres |

This is just me throwing out a gut answer: For eidolons- Nature's Soul, yes, since having it take handle animal is perfectly legitimate (they have more skill points than their summoners; sometimes you diversify out of combat and also take that sweet +8 to a skill evolution). No on animal ally, but mostly as a fiat, since this line of thought seems silly. I am against Matryoshka dolls when it comes to character concepts.
For animal companions- an animal is more in tune with nature and animals than other animals? Over all, no on both feats. The bit about 'limited intelligence' Irnk brought up also seems like a decent enough excuse. Even if you bumped your int to 3+, I would be inclined to deny both accounts. Also, I might feel that handle animal in general is impossible. Wouldn't it be diplomacy instead?

calicokat |
Like Deighton Thrane says, the distinction lies in the prereqs of Animal Ally:
Prerequisites: Nature Soul, character level 4th, must not have an animal companion or mount that advances as an animal companion.
When I got around to previewing my post he'd already answered the question, but that still leaves me to ask what animal companions' and eidolons' levels are called.
Are they simply "animal companion level" and "eidolon level"?