Records exist of a revived fossil that evolved into Rampardos. It proceeded to escape and then destroy a skyscraper with a headbutt. Its skull withstands impacts of any magnitude. As a result, its brain never gets the chance to grow. Its skull is as hard as iron. It is a brute that tears down jungle trees while catching prey.
Pokédex entry #409
Rampardos in Pokémon GO
It's possible to hatch Rampardos from an egg?
No, Rampardos can't be hatched.