Knuckles (Hidden Palace Zone boss)

Knuckles
Game: Sonic & Knuckles
Level: Hidden Palace Zone (Sonic & Knuckles)
Hits to defeat: 8
Fought by: Sonic and/or Tails

Knuckles serves as the boss of Hidden Palace Zone during Sonic or Tails' stories in Sonic 3 & Knuckles. Ever since Robotnik crashed the Death Egg into Angel Island, Knuckles has been tricked into thinking Sonic and Tails were after the Master Emerald; and now, in Hidden Palace Zone, the echidna makes his final defence of the Emerald Shrine.

This was the first Sonic boss that isn't an Eggman robot (with the possible exception of Sandopolis' Guardian). Knuckles is able to unleash the full array of moves he has when player-controlled, including the spin dash and power glide, as well as a punch move when Sonic or Tails is stood right in front of him. The echidna can also block spin-dashes by ducking down.

Knuckles' head and legs/feet are vulnerable, but obviously not his fists. With that in mind, it is possible to successfully strike a blow to him in 3 ways: a) dropping on him from above when he is stationary; b) jump into him towards the rear when gliding; (hitting his fists while insta-shielding also counts) c) if he drops from a glide mid-screen, get behind him while he's still in the air and spin-dash into him before he turns round.

After eight hits, Knuckles is temporarily knocked out. The ominous sound of a disturbance from the Emerald Shrine, however, wakes him up; Sonic and Tails follow Knuckles to watch Robotnik steal the Master Emerald in his Egg-O-Matic. Knuckles then gets shocked by Eggman.