In the Portal narrative, Wheatley is one of several spherical "personality cores" developed to restrain GLaDOS, the main artificial intelligence that operates the Aperture Science facility, from becoming rampant, though Wheatley is later revealed to have been built to act as an "intelligence dampener" towards GLaDOS to hampering her capability for thought. Initially serving as a comedic foil to the player-character Chell during the first half of Portal 2, Wheatley becomes the main antagonist of the second half as he takes GLaDOS's place and wreaks havoc on the facility before Chell and GLaDOS cooperate to stop him. In addition to Portal 2, Wheatley has appeared in Team Fortress 2 and Lego Dimensions.
