E-102 Gamma is a robot created by Dr. Eggman and a main protagonist in Super Smash Bros. Crossover. E-102 Gamma was originally one of Dr. Eggman's faithful servants, but after several encounters with the heroes, Gamma decided to delete Dr. Eggman as his master, and defected to the heroes. Since then, Gamma is frequently seen working with Shadow the Hedgehog and E-123 Omega, the latter being of the same lineage as Gamma. E-102 Gamma is later killed by Mechtavius Destroyer, although his death isn't seen. E-102 Gamma is later revived after the recreation of the Smash Bros. Galaxy. In Season 32, Gamma and Omega are sparring with each other when Omega stops due to sensing something off. Gamma then watches Omega attempt to comfort Sonic the Hedgehog after he had left the Heroes of Legend. In Season 34, Gamma is reprogrammed by Mecha Sally and becomes a member of her expanding army.
- During his time as Dr. Eggman's servant, Gamma would occassionally slip up by letting the heroes know what the weakness of Dr. Eggman's machine, calling his advice "hints". While this could be considered a running gag, it can also be considered a foreshadowing of his defection to the heroes.
- Despite being a remake of the original E-102 Gamma (who was destroyed at the end of his story in Sonic Adventure), this version of Gamma retains some memories of the original, such as considering Amy Rose as a friend.