Petta--Petta is a petta. She's a very simple creature who would rather not hurt anyone, but she has some surprising and powerful weapons. Petta is also good to have around when you're hungry. Her "fur" really isn't fur at all. It is an edible fungus.

From Wizard Chase:

How do you describe a petta? I could say that they are about the size of a small Shetland pony, and that they look something like a South American tapir. You couldn’t describe one without mentioning that they don’t have skin or fur, yet they are very soft and warm. They talk, sort of—you’d mention that. You might say that their feet are big and flat, like those of an elephant. But all that would leave out the essential thing about a petta. Pettas are the most good-natured beast in the universe. At least, my petta was.