Vullaby

“Their wings are too tiny to allow them to fly. They guard their posteriors with bones that were gathered by Mandibuzz.”

— Pokémon Y

“Its wings are too tiny to allow it to fly. As the time approaches for it to evolve, it discards the bones it was wearing.”

— Pokémon Black

“They tend to guard their posteriors with suitable bones they have found. They pursue weak Pokémon.”

— Pokémon White