Black shell, and it would probably be like the Devil Tamagotchi. But instead of devils, it would have all kinds of mythological creatures that you could have it evolve into, nice ones like Pegasus to mean ones like Cerberus or demons or something.
I might also make one based off of Norse mythology, where you could get various creatures (Ygrdrasil, the dragon, Odin, Hunin & Munin, Loki, Sleipnir, and the likes.)
