I think that's very cool, Idk if I think by default elementals are very boring in design, but yeah I think there's room for new interpretations, really there physical form should not matter that much as it's got nothing to do with how they life, fight, move ect. A fire elemental is just a living bunch of flame it could really take any shape, hominid, amorphous mass of flame, a bird, dog or in your case an Ox.
Looks really cool, I might use in my own table top games if your okay with that.