A quick search of the standard model sites returns quite a few cheetah images. I'm no modeler, but it shouldn't be that difficult to take of the of ones in existance, animate it and cap it to a new file. Course then again, the existing one could simply be antialiased and it would look better.

The only problem I see with the current one is that its used all over by other sites and "artists" that claim they did it. You can even find it as an IM glyph.