Yamask

Yamask is a Ghost-type Halloween event-exclusive Pokémon from the Unova region. It can evolve into Cofagrigus after being fed 50 candies.

Trivia

 * Yamask is a Halloween exclusive Pokémon, which means it is not obtainable outside the events. This was confirmed from a Niantic's Reddit account.
 * Yamask is a Halloween exclusive Pokémon, which means it is not obtainable outside the events. This was confirmed from a Niantic's Reddit account.