Metal Knuckles is the First of Robotic counterpart of Knuckles, he also appears in Sonic Advance as Mecha Knuckles and Sonic Heroes, as a Palette swap of Knuckles used in Multiplayer.
Super Sonic RacingEdit
Metal Knuckles was built by Robotnik to help him gather the Chaos emeralds but was defeated by Sonic, Tails, Amy and his Template, Knuckles
Fake Guardian of Angel IslandEdit
See: Mecha Knuckles