E-102 Gamma is a battle robot created by Dr. Eggman, but later gained his own sentience when he learned of friendship from Amy Rose and turned on his creator. He then assumed his own mission to 'free' his robot brethren from Eggman, and succeeded, though at the cost of his own life. He was first introduced in the game Sonic Adventure as a playable character.
Gamma's gameplay involves the player utilizing his missile launcher to destroy enemies and eventually reach a boss/target within a given time limit. The more enemies the player destroys, the larger the score and extension of time for the given level. [Source: wikia]
You can download this paper model template here: Sonic Advanture - E-102 Gamma Free Robot Paper Model Download