- For the later robotic version of Knuckles, see Mecha Knuckles.
Metal Knuckles (メタルナックルズ Metaru Nakkuruzu?) is a robotic version of Knuckles who appeared in Sonic R as an unlockable character. It was created by Dr. Robotnik, and its abilities are similar to Knuckles'.
Sonic Channel featured a Japanese profile of Metal Knuckles. Translated, it states,
- "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."
In other media
Sonic the Comic
A similar character appeared in Fleetway Editions' Sonic the Comic, as a new version of Metallix that was loyal only to Robotnik. It made its debut capturing Sonic for the Drakon Empire and then acting as a Prosecutor in Sonic's trial-by-combat. It came very close to killing him, but Tails managed to destroy it by sheer luck. The Metallix was only reused once, as Grimer used it to defeat Sonic so he could discover from him what happened to Robotnik; he then faked things so Sonic wouldn't remember this and instead think he beat Metallix. In its three clashes with Sonic, the Knuckles Metallix has never been defeated. It was once shown that Robotnik had a whole army of them, but they were never shown in use.
Metal Knuckles also appears in Archie Comic's Sonic Universe #37 as part of the Metal Series, along with Metal Sonic, Metal Tails and Mecha Sally. He later reappeared apart from the others in Sonic the Hedgehog #243 as part of the Dark Legion forces attacking Albion.
- Curiously, while in Sonic R, Knuckles' own shoes are miscolored from his traditional design, Metal Knuckles' shoes are colored correctly.
- Another Knuckles robot appears in Sonic Advance, this one designed to resemble Knuckles moreso than the original.