#793 in the National Pokédex, Nihilego is the Parasite Pokémon, able to feed on people and Pokémon alike. It is of extradimensional origin, being an Ultra Beast from Ultra Space, codenamed UB-01 Symbiont. Its infestation releases a powerful neurotoxin which increases violent tendencies in its victims, giving it a Rock/Poison dual-type. Strangely, Nihilego has been observed acting similarly to a young girl.