Meet Diana Nadine Appel.

Di is a shapeshifting skunk with a double-helix pattern down her back. Like Cal, she was originally created by the artist as a throwaway character, specifically as a way to experiment with transformation sequences -- and, like Cal, she ended up becoming a permanent part of the artist's roster. Pairing them together just made sense.

Art by tabbiewolf, 2010
Diana by tabbiewolf