Skinny Pigs typically have hair on their muzzles, feet, and legs, but are hairless over the remainder of their bodies.

The term "skinny" is used for hairless guinea pigs either because it colloquially refers to the exposed skin of the animal, or because it describes their thinner appearance due to their lack of hair.

The hairless strain that it is most likely related to was a spontaneous genetic mutation that was first identified at Montreal's Armand Frappier Institute in 1978, in a colony of Hartley lab guinea pigs.

[6] Skinny guinea pigs should be housed indoors, and they are usually kept with nesting materials such as a blanket or cloth bag for heat conservation.

[4] The breeding protocol for Skinny guinea pigs requires outcrossing to haired carriers at least every other generation.

"Werewolf" is a slang term for Skinny Pigs with more hair than usual, extending up over the face and onto the neck and shoulders.