Fight-o-Plankton is a giant robot created by Plankton (Spongebob squarepants character) that is also controlled by him to stop "The Tortured One" (a giant starfish beast that is the antagonist of "The Bikini Bottom Horror" comic).
He has abilities like propelling himself with some kind of rockets in his back, using a giant chainsaw blade to cut things off, and a flamethrower that can create flames so strong water doesn't stop them at all. In this situation, he mistakes you as The Tortured One.