Are you making your own Familiars in Cats and Dogs? Share!

I haven't made them yet but I do plan on making a alchemist witch with a black cat .. yes I'm playing out a stereotype sue me :). I'm thinking about giving a fox to the wizard I have in the game since he lives in a remote area (Windenburg now... but I'll move him soon to Glimmerbrook) or one of the familiars that float like an owl or raven. I don't know if pet familiars work the same as the others but I understand the pets can go get things?