Mundane animals such as cats, dogs, foxes, wolves, raccoons, owls, ravens, ferrets, etc. ARE allowed, provided it is a non-speaking animal that acts naturally and does not have any magical talents. If you want to make a character like that, please see familiars.
Animals roaming around Ascension should be actual animals that would be found in the area (i.e. no elephants, giraffes, hairy-nosed wombats, etc). The avatar used must be a true animal, not anthropomorphic in any way.