I'm a little surprised there hasn't been a guide out for this yet up on the boards - so I guess I'll try to start one myself. I will need help from the rest of you to do this right though, so if you see something that's not on the list, or incorrect please post so I can add/fix it. This is going to be real skimpy at first, but hopefully we can add enough that anyone starting anywhere will be able to find the skills they want for their pet. Thank goodness for an edit button.
Notes:
To keep your current pet while you go out skill hunting you will need to put it into a stable. There is a one time cost for the slot.
The beast you are going to learn the skill from must use it in battle, you can not simply tame the beast then have the skill.
Not all pets will be able to use every skill. Example, a wolf may not be able to use claw, but can use bite.
Abilities
Growl Rank 1-5: Available from pet trainers in most cities.
Bite Rank 1: Webwood Silkspinner*;
Bite Rank 2: Coyote Packleader;
Bite Rank 3:
Bite Rank 4:
Bite Rank 5:
Claw Rank 1:
Claw Rank 2: Thistle Bear;
Claw Rank 3:
Claw Rank 4:
Claw Rank 5:
Cower Rank 1: Foreststrider Fledgling;
Cower Rank 2:
Cower Rank 3:
Cower Rank 4:
Cower Rank 5:
* Would like verification