- Not to be confused with Metal Knuckles from Sonic R, or Mecha Knuckles from the Archie comic series.
Mecha Knuckles (メカ ナックルズ) is the fifth boss battle in Sonic Advance, which takes place in Angel Island Zone. This robot attempts to imitate Knuckles the Echidna in appearance and attacks, though it first appears as a pink echidna with yellow gloves, catching the player's character by surprise. The colour scheme is similar to that which Knuckles used as an NPC in Sonic the Hedgehog 3.
The boss uses all of Knuckles' abilities, including punching, gliding and the Spin Dash, and will also block the player's Spin Dash when in its regular position. Basically, if the player has fought Knuckles in Sonic & Knuckles/Sonic 3 & Knuckles, then they already know what to expect.
The player should not attack it when it is Spin Dashing, or attempt to attack from the front while it is gliding. They can attack it with a jump or a attack while it's standing, in mid-glide from below, or when it stops gliding. After it takes four hits (or three if playing in Easy mode), it will take on its true form (a silver-colored mechanical echidna with yellow gloves, gray shoes & red "insect" eyes) and turn more aggressive by shooting missiles out of his mouth, which can be difficult to dodge as they will slightly home in on the player at high speed, requiring good timing to jump over. Its other attacks, such as gliding, will also become faster. The player must inflict four more hits on this robot to destroy it (or three more hits if in Easy mode), forcing Dr. Eggman, who was observing the battle from off-screen, to retreat.