Super Arm

Super Arm (スーパーアーム) is Guts Man's special weapon. In the first Mega Man game, the Super Arm does not fire on its own. Instead, Mega Man must walk up to certain blocks, and if they can be picked up by the Super Arm, they will flash. Press the attack button to pick them up and press it again to throw them. If there is not enough room available to create an arc, or if/when they land on the ground, the blocks will scatter. In the two arcade games Mega Man: The Power Battle and Mega Man 2: The Power Fighters, boulders appear for the player. You can't climb while performing this.

Bosses Weak Against Super Arm

 * Cut Man: Mega Man and Mega Man: Powered Up
 * CWU-01P: Mega Man
 * Ice Man: Mega Man: The Power Battle
 * Yellow Devil: Mega Man: The Power Battle
 * Air Man: Mega Man 2: The Power Fighters
 * Wily Machine: Mega Man 2: The Power Fighters

Bosses That Can't Be Attacked By Super Arm

 * Bomb Man: Mega Man
 * Copy Robot: Mega Man
 * Fire Man: Mega Man
 * Ice Man: Mega Man
 * Yellow Devil: Mega Man
 * Buster Rod. G: Mega Man: The Wily Wars
 * Mega Water. S: Mega Man: The Wily Wars
 * Hyper Storm. H: Mega Man: The Wily Wars
 * Fire Snakey: Mega Man: The Wily Wars
 * Iron Ball: Mega Man: The Wily Wars
 * Wily Machine: Mega Man and Mega Man: The Wily Wars

Other media
Proto Man uses the Super Arm against Mega Man in the first episode of the Mega Man animated series. This is the only special weapon he took from a Robot Master.