Gamma is a giant peacekeeping robot created by Dr. Light and Dr. Wily. In the story to Mega Man 3, Wily claims to have renounced his evil ways and wishes to work alongside his former colleague Light once again. Together they build a new robotic peacekeeper - Gamma. Shortly after construction, Gamma is stolen and Dr. Wily reveals that he intended to use it to conquer the world the whole time. It is later destroyed by Mega Man.
Gamma is the final boss of Mega Man 3. When first confronting Gamma, it has a small head attached to its incomplete head that fires pellets. It will also try to strike Mega Man with its fists, which Mega Man can jump on to reach its weak point. The small head is vulnerable to Shadow Blade and Hard Knuckle.
When the smaller head has been destroyed, a large helmet will connect to Gamma's head which is piloted by Dr. Wily. Gamma will continue with its punches and fire energy blasts from its mouth. At this point, Gamma is weak against Search Snake and Top Spin.