Sometimes all you need is a model of a cow.
Lyndon Daniels writes:
Two digital characters are available, free for download, including realtime horse and cow 3D models. Each model comes with it’s own 2048*2048 textures including a Color Map, Normal Map and Ambient Occlusion Map. The models are available under CC0.
The models were made in Blender 2.5 and the textures were done in the GIMP 2.6
More details about the models and images can be found on my website.