Skallyk

Black +2: 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.

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

Black 2 +3: Their wings are too tiny to allow them to fly. They guard their posteriors with bones that were gathered by Mandibuzz.

Sun: It protects its plump posterior with the bones of prey it has consumed. As it grows, it replaces the bones.

Moon: It can’t fly yet and must wait until its wings have developed more. Since it’s still at a playful age, it hops around friskily.

Ultra Sun: Mandibuzz gives it the bones it wears. Vullaby’s wings are short, so it can’t fly yet, but it jumps around, dreaming of wide open skies.

Ultra Moon: Its healthy appetite leads to visible growth spurts. It often has to replace the bones it wears as its size increases.

Sword: It wears a bone to protect its rear. It often squabbles with others of its kind over particularly comfy bones.

Shield: Vullaby grow quickly. Bones that have gotten too small for older Vullaby to wear often get passed down to younger ones in the nest.