1). A living creature.
2). A domestic animal, especially a cow, horse, or mule.
3.) A person.
Sorry, but the correct definition (mine) is a combination of these. Simply stated, my definition, at least in terms of this gallery, is a living creature EXCEPT for a person. Doesn't matter if it's domestic or wild; if it's living and not human, it's a critter.
Note: Although I live within an easy drive of the Arizona-Sonora Desert Museum, one of the world's greatest zoos, and visit there regularly, I've opted to include here only photographs from the "wild"... mostly taken while hiking, with some that were seen from the road. (My own dog Sadie is one exception, but anyone who has met her would definitely agree that she counts as "wild" as much as any of the others seen here; "pets" are also seen in a couple of additional photos. Cows and horses aren't terribly fierce either, but I've photographed many of them. It's so easy and fun to get cows to look at you simply by mooing. They're probably thinking "We're supposed to look up now because another idiotic guy with a camera is here.")
See the album "At The Zoo" for animals photographed in captivity.
Here are some of my favorite critters that I've encountered through the years.