Even while under careful observation, large flocks of Drifblim flying at dusk will inexplicably disappear from view. It carries people and Pokémon when it flies. But since it only drifts, it can end up anywhere. It’s drowsy in daytime, but flies off in the evening in big groups. No one knows where they go.
Pokédex entry #426
Drifblim in Pokémon GO
It's possible to hatch Drifblim from an egg?
No, Drifblim can't be hatched.
Which are Drifblim’s strengths and weaknesses?
Drifblim is a flying and ghost type Pokémon. flying type pokémons are strong against grass, fighting, bug pokémons but weak against electric, rock pokémons. ghost type pokémons but weak against psychic pokémons.