My newest pet,

Haxan (currently an arid Charlie), will eventually become a Nightmare pet, but I'm unsure about species (and perhaps gender?).

The name comes from the spooky silent film, Haxan.
I don't have a character for this pet, per se. It will be conceptual and based on the overall feel of the movie. The nightmare color works really well with the film's aesthetic, as it was in black and white and focused on satanic themes throughout. (It's a great Halloween watch, and it's in the public domain, btw.)

Häxan is the Swedish word for witch, implying a female pet with witch-like features, but I don't know that I want to apply the name so literally with this concept. I'm leaning towards something with horns, but it isn't 100% necessary.

I hope I'm making some sense. Heh.

Image below related. It's a screenshot of what is probably the most iconic imagery from the movie.