Misuse of this category
I have seen this category misused several times, a lot of them by people who fail to realise that "antagonist" is not necessarily the same thing as "villain".
An antagonist is simply someone who opposes the protagonist(s); this could be for innocent, non-evil reasons, such as Rita Malone who has good reasons for opposing Roddy St. James at first. An even more extreme example is the crocodile from A Matter of Loaf and Death (neither of these are anything to do with DreamWorks, hence shouldn't be on this wiki; I thus haven't linked them), which attempts to eat Piella's dog and ends up eating Piella, but neither of these are evil acts as it was just acting the way nature programmed it to act. It is thus an antagonist but not a villain.
Feathers McGraw from A Close Shave on the other hand, although an (anthropomorphic) animal, is acting with conscious evil intent, hence is a villain.