First Seen: Sonic R (1997)
Metal Knuckles is an artificial copy of Knuckles the Echidna created by Doctor Ivo "Eggman" Robotnik, and appears as an unlockable character in Sonic R. Much like Metal Sonic, Metal Knuckles was created with the intention that it would destroy its biological counterpart.
As with Sonic, Eggman prepared this secret weapon for the sake of overthrowing Knuckles, considering his existence to be a hindrance. Having the same power plant as Metal Sonic, speed and acceleration power are high, but like Knuckles, this robot can glide from high places.
[Appearance requirements] Collect 5 tokens in Reactive Factory in Grand Prix mode and finish better than fourth place to begin a one-on-one match with Metal Knuckles. Win this race and Metal Knuckles will become a possible choice on the character select screen.
— Sonic Channel
Metal Knuckles is often cited as the second-best racer in Sonic R, consistently beaten only by Super Sonic. Along with Metal Sonic and Tails Doll, Metal Knuckles completes Sonic R's set of artificial copies for Team Sonic. The robot's debut is his only appearance to date.
|Sonic the Hedgehog (game series) characters|
|Heroes||Sonic (Super, Hyper, Darkspine, the Werehog, Excalibur) | Tails (Super) | Knuckles (Super, Hyper) | Amy Rose | Cream | Blaze (Burning) | G.U.N. Commander | Emerl | Silver (Super) | Marine | Shade | Lumina Flowlight | Chip | Shahra | Knights of the Round Table | Caliburn | Yacker | Sticks|
|Anti-heroes/ Neutrals||Shadow (Super) | Rouge | Espio | Charmy | Vector | Mighty | Ray | E-102 Gamma | Chaos (Perfect) | E-123 Omega | Bean | Bark | Jet | Wave |Storm | Merlina | Illumina|
|Villains||Dr. Eggman | Metal Sonic | Mecha Sonic (Super) | Metal Knuckles | Tails Doll | E-Series | Fang | Gemerl | Eggman Nega | Battle Kukku Army | Biolizard | Black Doom | Ix (Super) | Void | Iblis | Mephiles | Solaris | Dark Gaia | Witchcart | Erazor | King Arthur | Orbot | Cubot | Deadly Six | Lyric | Hard-Boiled Heavies | Infinite|
|Teams||Sonic/Heroes | Rose | Dark | Chaotix | Babylon|
|Other||Gerald & Maria Robotnik | Big | Chao | Tikal | E-101 Beta | Heavy and Bomb | Flicky | Animals|