The Colossus of Rhodes is a robot.
The Colossus of Rhodes is a gigantic automaton created by Ancient Greek engineer Chares of Lindos around 290 B.C. to help and protect the Island of Rhodes. Though the Colossus's body was the work of Chares, its programming was contained in three disks of unknown nature, which originated in Atlantis. The original disks, yellow, green and blue, corresponded to three settings: the yellow disk made the Colossus defend the island from invaders, the green one made it help with heavylifting, and the third was a failsafe that would make the Colossus head off to Atlantis if it was in need of repairs.
After a King of Rhodes grew power-hungry, a fourth disk was built, meant to go in the slot normally reserved for the blue disk: the Black Disk, built for war. Fortunately, the inner workings of the Colossus contained a failsafe that would prevent the Colossus from being used for war, and as a result, it short-circuited when the Black Disk was installed. Before the powerless inhabitants of Rhodes' very eyes, the Colossus walked into the see, never to return, before growing still at the very bottom.
In 2005, a diver named Pericles found the frozen Colossus. Amazed, he cut out the Black Disk to bring back a proof of his discovery. Unbeknownst to Pericles, this unjammed the Colossus, who reverted to Yellow Disk mode, patrolling the sea to protect Rhodes. Meanwhile, power-hungry maniac Doctor Malvazar had been constructing a war-oriented copy of the Colossus from Chares' original plan, the Shadow Colossus, but still needed the Black Disk to make it work.
The carved-out Disk ended up in Malvazar's possession and the Shadow Colossus went on a brief rampage. It was, however, delayed by the original Colossus who fought back, before the failsafe (that Malvazar had unwittingly replicated in the Shadow Colossus) kicked in and the humongous machine collapsed. Having been damaged in the fight, the Colossus got Eurasia Toft to put the Blue Disk back where it belonged, and the battered Colossus subsequently headed off to Atlantis.
Behind the scenes
The Colossus of Rhodes was first seen in the 2005 story Mickey Mouse and the Shadow of the Colossus.