The first form of taxidermy was Egyptian mummification

Taxidermists have mounted creatures from mice to elephants, and even created fabulous beasts.

Taxidermists don't actually stuff animals
They mount the skin on a sculpture of the animal. While some ready-made mounts are available, a taxidermist often creates the sculpture from scratch. So taxidermists must be experts on anatomy and art as well as the removal and preservation of skins.