Zweilous

Zweilous is the evolution of Deino, and the pre-evolution of Hydreigon. It now has two heads. It evolves into Hydreigon at level 64.

Appearance
Like Deino, Zweilous is a blue dinosaur-like Pokémon, but after evolving, it gained a second head. Black fur covers both heads' necks and eyes. Two wings have also appeared after evolving. On the end of each front leg are two claws. It has a stubby tail and two feather-like "horns" on both of its heads. Its underbelly has two rows of magenta scales.

Trivia

 * Zweilous evolves at the highest level of any Pokemon (level 64).
 * It's name appears to be combination of Zwei, the german word for the number 2 (referencing Zweilous' number of heads) and envious or jealous, since one head is always competing with the other. For instance if one head ate more than the other, the other would be jealous of the other.
 * It seems to have a pair of wings growing or developing on its back.
 * Basculin and Zweilous are the same species, both being the Hostile Pokemon.
 * No Trainer in Generation V games, has Zweilous. It shares this trait with Rufflet, Vullaby, Mandibuzz, and Ferrothorn.