Nihilego

“One of several mysterious Ultra Beasts. People on the street report observing those infested by it suddenly becoming violent.”

— Pokémon Sun

“One of the Ultra Beasts. It’s unclear whether or not this Pokémon is sentient, but sometimes it can be observed behaving like a young girl.”

— Pokémon Moon

“A life-form from another world, it was dubbed a UB and is thought to produce a strong neurotoxin.”

— Pokémon Ultra Sun