Operation: Last Resort is an event that appears in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics. It was a contingency plan set in motion by Sally Acorn of the Knothole Freedom Fighters.
Following the failure of both Bunnie Rabbot and Knuckles the Echidna to stop Mecha Sonic from devastating Knothole Village, Operation: Last Resort commenced. As its name implies, the operation called for the last thing the Knothole Freedom Fighters would willingly do-namely, subjecting a Mobian to Roboticization in order to combat the similarly transformed Sonic the Hedgehog. Recovering from his first bout with the enslaved Robian, Knuckles donned a Neuro-Overrider device so as to retain his free will. Entering a Roboticizer, he emerged as Mecha Knuckles and once again engaged Mecha Sonic. After a brutal battle that included the near destruction of both combatants and great damage to Robotropolis following the explosion of a stockpile of nuclear warheads, Mecha Knuckles emerged victorious. Returning to Knothole Village with his defeated enemy, he was De-Roboticized, as was Sonic, bringing an end to Operation: Last Resort.