Because Metalhead had all the Turtles' brain-wave patterns, it was subject to dissociative identity disorder, exhibiting different personalities from one minute to the next. Donatello reprogrammed Metalhead to fight for the Turtles, but after being shot by Bebop, it malfunctioned and attacked everyone. Donatello was able to rig some of the broadcasting equipment at the Channel Six News Building to reprogram Metalhead. As a result, Metalhead realized that the Turtles were his friends and protected them from Bebop and Rocksteady. When the Turtles were ill at the end of the episode, Metalhead became their new nurse.
He was only seen again when Donatello tried to get him to vacuum their TV room in episode Big Bug Blunder. This backfired, as he began vacuuming people and sucking up objects like rugs, forcing the Turtles to shut him down again.
His original action figure bio described him as "The original Party robot!". The figure featured an arm with swappable mecha-nunchuks, a backpack with scanner and video games, and vac-metallized detailing. The figure was later re-issued as a roboticized Michelangelo.