So recently I started having a problem which changes the size of some vanilla wildlife, making wolves, bears (black and brown), and dogs about 2 to 3 times as big as they should be, and mudcrabs about 6 times normal size. Only the base creatures are changed, not other versions, so named dogs are the normal size, so I think it's in a mod, not a bug in the models or the game. I'm using a couple mods, but the problem only started some time after I got Natural Environments and Elsweyr, Deserts on Anequina, but a friend of mine who doesn't use either of those mods has had this problem for a while. Any idea what causes it?

If you disable your mods one by one and test the game you could find out if it is one of them. If not... perhaps backup your saves and reinstall?

This actually sounds really cool, giant mudcrabs and wolves the size of men, I wish I could get that to happen for me. But as for how this happened...well, Oblivion is a strange game with many things that cant be explained, this just adds to that list I guess :shrug: