Yamask (Japanese: デスマスDesumasu) is a Ghost-typePokémon introduced in Generation V. Yamask are often found near ancient desert burial sites guarding treasure and bodies. There are many artifacts depicting this Pokémon. 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. Yamask and Cofagrigus have the new Mummy ability.
Yamask is a black, shadow-like figure with two limbs protruding from its upper body. On the end of its "tail", it holds a gold mask. Yamask's eyes are red with a small black pupil in the middle.
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 possessed him as well as commanding a whole bunch of artifacts including a Dragonite fossil to attack Ash and Iris.