"I think I hear the bird! Pick me up!"

"No, wait. Just kill it and we'll call things even between us. No hard feelings."

GLADOS (Genetic Lifeform And Disk Operating System) is an Artificial Intelligence created by Aperture Science, and the primary antagonist of the Portal series. She is the main antagonist throughout Portal and the first half of Portal 2's single-player campaign. As the overseer and highest of authorities of the Enrichment Center, GLaDOS resides in the Central AI Chamber.

After Wheatley and Chell triggered a Core transfer that, detached GLaDOS from the mainframe and replacing her with Wheatley.Gloating, he celebrates his newfound power by humiliating GLaDOS further, attaching her to a potato battery capable of powering only her consciousness and most basic functions. However, he suddenly turns against Chell because he "Has done nothing but sacrafice himself". GLaDOS proves she is still not entirely helpless: she quickly goads Wheatley into a rage, and he knocks them into the bowels of the facility. GLaDOS' potato is carried off by a bird, but Chell eventually finds her. Desperate, she talks Chell into teaming up with her to defeat Wheatley.