In the process of creating some artwork for the Sokoban Game Blendenzo and I are making, I created this fairly realistically proportioned donkey model. We don’t have a use for it now, and it does no good sitting around on my hard drive, so click here and enjoy. 
There are high-ish and low poly versions, and they are both roughly UV-mapped, but are not rigged, animated, textured, etc; so it may take a little work to get them in your game, but they are licensed under a very free Creative Commons license, so you can do pretty much whatever you like with them.
You’ll need to apply the mirror and/or edge split modifiers before using them in-game, as well, or only half the model will show up.
- Clean3d
