GLaDOS

The Genetic Lifeform and Disk Operating System, also know as GLaDOS, is a giant robot that operates the entire Aperture Science Enrichment Center, and the main villain in the crews Portal 2 series. She was the reason behind the creation of ATLAS and P-body, and why they were caused so much mayham. She constantly tries to annoy the duo and almost seperated them at one point, but Knightclub caught onto her game and kept the gang together. While she was a major menace to the crew and their tests she never made a physical appearance, but we should know what she looks like by now. She wasn't defeated or killed in any known way in the co-op campaign, so lets not worry about that.

Trivia

 * GLaDOS is technically the first REAL antagonist in the crew's series, and she won't be the last since season 3 marks the BGG era.
 * GLaDOS is constantly called out on by the crew, either by being told to shut up, saying that no one cares what she thinks (which really we don't) or simply being called a bitch.
 * GLaDOS has mixed fellings about Blue and Orange, but overall hates both of them.