Gamma

Gamma (ガンマ) is a giant peacemaker robot constructed by Dr. Light and Dr. Wily. During Gamma's construction, Dr. Wily feigned peacefulness, gaining Dr. Light's trust and assistance long enough to complete the big robot. Dr. Wily's true intentions were to use the enormous creation as a weapon, furthering his evil plans for world domination.

Strategy
Gamma is the final boss from Mega Man 3. In its first form, it has a small blue head that shoots from its mouth. The simplest way to defeat this form is to stand directly underneath the head and use Shadow Blade. Alternately, the head is also weak to Hard Knuckle. After destroying the small head, Wily completes Gamma's head and controls him, attacking with shots and punches. Gamma's second form is very vulnerable to Top Spin, and can be defeated in seconds by using it rapidly against Wily; but if desiring more of a challenge then use the Search Snake.

Captain N: The Game Master
In the cartoon, Gamma is a giant yellow ball robot with blue details. He has a large smile and the peace symbol drawn on him, as Gamma was originally created for peace. It also has a cockpit in the top of his head, where Dr. Wily controls it.

Rockman Gigamix
In the manga, Gamma appeared in the story "Asteroid Blues", which is based on the events of Mega Man 3. Mega Man fights against him in space. Gamma also had a brief appearance in the beginning of the story "Metal Heart" from Mega Man Megamix.

Trivia

 * Gamma (Γ) is the third letter of the Greek alphabet. He is the first in the Mega Man franchise to have a Greek letter for a name although three other characters, Epsilon (Ε), Sigma (Σ) and Omega (Ω), share the same naming convention.


 * Gamma's small head during its firs form seems to have the Greek letter, Gamma (Γ), on its forehead.
 * In X5, Sigma's 2nd form is somewhat modeled after Gamma as well as shares the same name, being more properly referred to as Gamma Sigma.