- Not to be confused with Metal Knuckles from Sonic R, or Mecha Knuckles from the Archie comic series.
Mecha Knuckles is the fifth boss battle in Sonic Advance, which takes place in Angel Island Zone. It's a pink echidna with yellow gloves, and is based on Knuckles the Echidna's appearance. The boss uses all of Knuckles' abilities, and it will also block Spin Dash and special attacks when in his regular position. Basically, if you've fought Knuckles in Sonic & Knuckles/Sonic 3 & Knuckles, then you already know what to expect.
Do not attack him when he is Spin Dashing, or attempt to attack from the front while he is gliding. You can attack him in mid-glide from below. After it takes four hits (or three if easy mode), he will take on his 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 will slightly home in on you. The player must inflict a total of eight hits on this robot to defeat it (or six hits if in easy mode).