Sharp Knuckle is a Special Weapon exclusively used by Knuckles Man in the Sonic the Hedgehog and Mega Man comic crossover, Worlds Collide. Upon using this move, the user can punch an object/opponent to a great distance via the user's sharp knuckles, hence its name. When Mega Man uses this Special Weapon, he turns into a red and white attire and has actual spikes on his knuckles.
During the First National Bank Robbery in Mega City, Proto Man had faced against Knuckles Man, Shadow Man, Tails Man, and Rose Woman. Knuckles Man had used his Sharp Knuckle ability to punch away Proto Man's shield. Later, when Mega Man, Proto Man, Sonic the Hedgehog, Miles "Tails" Prower, and Rush went to Skull Egg Zone, all, excluding Tails Man, of the Roboticized Masters—Shadow Man, Knuckles Man, Rose Woman, Blaze Woman, Silver Man, Vector Man, Charmy Man, and Espio Man—ambushed and tried to attack the heroes. Knuckles Man used the Sharp Knuckle Special Weapon on Sonic, but it had failed quickly. (WC #1, #2, #5, #6)