Yamask

Yamask is a Pokemon that first appeared in the Generation V games Pokemon Black and White. Yamask is Cofagrigus's pre-evolution. It evolves into Cofagrigus at level 34. Yamask are often found near ancient desert burial sites guarding treasure and bodies. There are many artifacts depicting this Pokemon. They were thought to be extinct until an archeological dig unearthed a golden mask. That night, the mask disappeared. The next night they found the mask floating in the air with a singular eye floating above its head. When they shined a light at it they realized it was Yamask.

Trivia

 * Yamask appears in the episode BW014: Shippou City! Big Adventure at the Museum of Pokemon: Best Wishes!. It is seen in the preview lodged on Cilan's face and possesed him as well as commanding a whole bunch of artifacts including a Dragonite fossil to attack Ash and Iris.
 * It's head crest is similar to that of Gallade.