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.
DUSCLOPS absorbs anything, however large the object may be. This POKéMON hypnotizes its foe by waving its hands in a macabre manner and by bringing its single eye to bear. The hypnotized foe is made to do DUSCLOPS’s bidding.
It is thought that its body is hollow with only a spectral ball of fire burning inside. However, no one has been able to confirm this theory as fact.
Its body is entirely hollow. When it opens its mouth, it sucks everything in as if it were a black hole.
Its body is hollow. It is said that those who look into its body are sucked into the void.
— Pokédex entries (via PokeAPI)