The Darkness is a Beverly Hills ChihWALL-E character. His main role is to curse WALL-E City and do evil. There is a truth about him, but no one knows except... us. Here is his truth:
The truth about the Darkness
We remember the Auto-Bot. You know, the evil "main" captain of WALL-E. He got shutdown, and everything was down to earth. But 1 year later, at the night before the 1 year anniversary of WALL-E and EVE saving the humans, Auto-Bot was switched back on. How? Well, remember the computer mouse mouses down from the garbage wasteland? They somehow got into the Axiom's main control center and turned back on Auto-Bot. When he saw he was on Earth, he got so furious, that he magically turned into the Darkness. He grew till next day, smashing the room of the Axiom, which was at the desert. So he traveled and ruined the parade like in the movie. That's how he came to be.
His death is when WALL-E used the Chaos Emeralds lying around in a shelf in the human's jail cell and defeated the darkness with it's harnessing power. And the land was not cursed anymore...