Doominator

The Doominator is a huge robot that was set to destroy Wumpa Island forever. Cortex's plans was to build the robot and destroy Wumpa Island himself, but in the story Uka Uka replaced Cortex for Nina Cortex, then Nina kiddnapped Coco Bandicoot and brainwashed her into her building the robot while Crash and Aku Aku are searching for Coco. Coco is finished and the Doominator is complete, Nina and Cortex are about to let the Doominator do its job, but right when hope is lost for Wumpa Island Crash reaches the main control room of the Doominator, Crash then deafeats Nina and destroys the the giant machinery. Coco returns to her normal self and uses the purple thingy (that Crash had all the time) to shut off the Doominator, the Doominator then falls and crashes on top of Wumpa Island. The remains of the Doominator are able to be seen (and near the end, entered) in the new game Crash: Mind Over Mutant.

Trivia
The Doominator was orignally built to destroy Wumpa Island, but in the Nintendo DS version, the robot is named "The Cortexbot" and it's only supposed to "boogie".

The 1st boss of Crash: Mutant Island looks very similar to the Doominaitor.