Golem cannot be caught in Pokemon FireRed version. It is only obtainable in FireRed by evolving Graveler.
Golem belongs to the Megaton Pokemon species with special abilities like the Rock Head move, which prevents it from recoiling, and Sturdy, which prevents it from being knocked out with one-hit KO moves. Its body resembles a large boulder, and it has claws on its hands and feet. In the FireRed version, players with Graveler can evolve it into Golem at any level when traded.
Graveler is a rare Pokemon in FireRed. It can be found in several locations, namely the Cerulean Cave, Rock Tunnel, Kindle Road, Sevault Canyon and at Mt. Ember. Alternatively, Geodude, a more common Pokemon, can be caught, and it will automatically evolve into Graveler at level 25.