A little corn snake we found dead in the back yard.
Cut it open with an xacto knife, fed the innards to Diane, pinned it on cardboard and sprinkled with salt to dry out, and pepper to deter the flies. Set it out for a night, then (because it was a rainy, cloudy day) put it in a dehydrator. It can also be put in the sunshine to dry.
It's pretty pliable, and will hold stitches. I'm not sure if it can get wet, but I'll test that out later.
It's only about 6 inches long--a little baby corn snake.