Dusclops

Dusclops is a Ghost-type Pokémon from Hoenn region. It evolves from Duskull after being fed with 50 candies. Dusclops is also one of the first five Pokémon originally known from Hoenn region that were made available to catch in the game.

Pokédex description
Beckon Pokémon

''Dusclops's body is completely hollow—there is nothing at all inside. It is said that its body is like a black hole. This Pokémon will absorb anything into its body, but nothing will ever come back out.''

Evolution family
Dusclops is part of a two-member family.

Trivia

 * Dusclops was one of the first five Hoenn-region Pokémon released during the Halloween 2017 event.
 * Since Generation IV of core series games, Dusclops evolves into Dusknoir, but in Pokémon GO it's currently not possible.