GLaDOS

GLaDOS (Genetic Lifeform and Disk Operating System) is a fictional character from the video game series Portal. The character was created by Erik Wolpaw and Kim Swift, and voiced by Ellen McLain. GLaDOS is depicted in the series as an artificially superintelligent computer system responsible for testing and maintenance in the Aperture Science Computer-Aided Enrichment Center in all titles. After betraying and almost killing the player, she is revealed to be responsible for the desertion of the Enrichment Center after going rogue and killing the scientists who created her. She is disabled as the final boss of Portal. She is revived as a minor antagonist in Portal 2, but is supplanted by Wheatley and instead accompanies the player as their main NPC companion after being downloaded onto a potato battery nicknamed PotatOS. Recordings by Cave Johnson reveal GLaDOS to have been forcibly digitized from a human woman named Caroline.

The inspiration for the character's creation extends from Wolpaw's use of a text-to-speech program while writing lines for the video game Psychonauts. Other game developers working on Psychonauts found the lines funnier as a result of the synthesized voice. GLaDOS was originally intended to be present solely in the first area of Portal; she was well received by other designers and her role was expanded as a result. Play testers were motivated to complete tests in the game due to her guidance. While the game was initially designed with other characters, they were later removed, leaving GLaDOS as the only character players encounter. McLain imitated dialog read aloud by a speech synthesizer with her own voice, which was then processed to sound more robotic, and performed songs in character during the closing credits of both entries in the series. "Still Alive" became hugely successful, notably appearing in the Rock Band game series, and has been a popular song for YouTube users to cover. GLaDOS later appeared in The Lab and Lego Dimensions.