feral

An animal character that is depicted in its natural (real) form.

Ferals usually move on four legs (if they have legs at all), but this category also includes naturally bipedal animals such as kangaroos, birds, and various dinosaurs. In these cases the difference between anthro and feral can be subtle, but can usually be determined from the neck and shoulder shape, and the overall posture.

Fictional creatures are also included, if they resemble real animals.

Species that are normally quadrupedal (such as all feline, canine, and equine species) — or otherwise non-bipedal (such as legless, hexapod, octoped) — are by default either anthro or animal humanoid when drawn as bipeds. For example, a fictional canine-like species that walks on two legs is anthro, because feral canines are quadrupedal.

Non-animal characters such as plants or animated objects should never be tagged as feral, unless they're animal hybrids or otherwise strongly resemble animals.

Note that for tagging purposes, the level of intelligence (sapience) does not matter. For example, Scooby-Doo is still a feral even though he thinks and talks just like his human friends.

copied from e621 wiki