Gamma

Gamma (ガンマ Ganma) is a giant peacemaker robot constroed by Dr. Light and Dr. Wily, that pretended to be good to have help from Dr. Light and use Gamma in his plans. It is the final boss from Mega Man 3. Sigma took a similar form in Mega Man X5.

Fun facts

 * Gamma (Γ) is the third letter of the Greek alphabet.