Animals Inside Out: An Educational Exhibit, If You Can Stomach It

... The 100 animals in the exhibit are all skinned. 

Relax.  They are dead.  And they died humanely because they could
not be saved from whatever disease or injury they suffered, not because
someone wanted to skin them.

Great ape, plastinated: © Gunther von Hagens, Institute for Plastination, Germany

But after death, they were transported from their respective environs by veterinarians to the laboratories of German scientist, Dr. Gunther von Hagens so that he could very gently and carefully remove their skins through a process he developed in 1977 called plastination.

Plastination is a preservation process invented by von Hagens to enhance medical and scientific knowledge of each species of animal.  It is conducted by removing alll water and fatty tissues from the body and replacing them with polymers. The process stops decay of the remaining body tissues immediately.