Drifblim

“At dusk, swarms of them are carried aloft on winds. When noticed, they suddenly vanish.”

— Pokémon Black

“It’s drowzy in daytime, but flies off in the evening in big groups. No one knows where they go.”

— Pokémon Diamond

“It carries people and Pokémon when it flies. But since it only drifts, it can end up anywhere.”

— Pokémon Pearl