Hydreigon (Japanese: サザンドラ Sazandora) is a dual-type Dark/Dragon pseudo-legendary Pokémon. It evolves from Zweilous starting at level 64. It is the final form of Deino.
Hydreigon is a three-headed, dragon-like Pokémon. Hydreigon has six black wings on its back, which are similar to those of Giratina's Origin Forme. On Hydreigon's neck is a fuchsia-colored flower-like collar which opens to its head. The main head is a dark blue and its eyes are black with fuchsia pupils. Its hands, also black, harbor a head in each one; these heads are also blue with black eyes. There are small collars on the inside of Hydreigon's hands. On its abdomen are two overall-like fuchsia stripes. Its feet appear atrophied, having no claws or defined soles and two or three small toes. Its tail also sports a fuchsia stripe with a black tuft on the end of it.