As a rock, you won't be able to jump but you can harm anything you walk into. Shed your geological armor by hitting B.”
— Description • Nintendo Power
Giant Stone is a Combo ability in Kirby 64: The Crystal Shards obtained by mixing two Stone abilities. The ability allows Kirby to turn into a giant golem. He is invulnerable in this form, but he cannot jump. If Kirby stands on a slope, he will roll down, defeating any enemy he touches. Pressing the attack button while Kirby is a golem will cause Kirby to return to normal, leaving behind a blast of smaller rocks around his body, which can defeat enemies and is effective against bosses. It is functionally similar to the Metal ability in Kirby: Squeak Squad, although Metal Kirby can jump, float and cannot detonate himself.
Kirby looks more like a giant brownish, black statue of his glory. He has black hollow eyes, more like Kabu, but his eyes have a surprised-like expression. Usually, Kirby's eyes are blue, but now they are deep black.
Kirby becomes a rock that will slowly roll. By moving, Kirby will become a behemoth sized version of himself and crush anything in his path. By pressing B again Kirby launches all the rock off him and damages enemies.
Giant walking stone Kirby.”
— Description • Official Strategy guide
Kirby takes the shape of a giant boulder. He can still walk and jump a little distance, but his most spectacular power is his explosion when you press B.”