Betty

Betty, also known as the Gyroscopic Liability Absolver and Disc Operating System, is a cut core-based robot that was to appear in Portal 2.

Overview
Early in Portal 2's development, while Mel was still the main playable character, Cave Johnson, at that time the antagonist of the game, would introduce the player to each chamber in a similar manner to the one used by GLaDOS during the events of Portal. Betty was to "roll out after [he] had described the test," and give a disclaimer that would bar Aperture Science of any responsibility or dangers during the course of testing.

Trivia

 * Betty's technical name (GLAaDOS) was to be the only reference to the original character in Portal.