Gemerl

Gemerl is an android created by Doctor Eggman, from the data of another robot named Emerl, an ancient battle weapon who had recently been destroyed ("Sonic Battle"). Gemerl possesses many weapons and skills, including the ability to merge with the Doctor's vehicles and act as co-pilot. He had once used the power of the chaos emeralds to transform into a destructive orb-shaped machine, and turned against his creator as a result ("Sonic Advance 3"); ultimately, it took the combined efforts of Sonic and Doctor Eggman to put him out of commission. Afterward, Gemerl was found on the beach, unconscious, by Cream; Tails repaired the robot then, and Cream and Gemerl became friends. In the "Dimension" saga, however, Gemerl appears as the Doctor's robot once more, having evidently been reclaimed.

(editing shall recommence soon)