A nickname given to the stick figures seen in the Investment Opportunity virals, Bendy is a playable test subject in the various alternate universes of the Aperture Science Enrichment Center throughout the Perpetual Testing Initiative in Portal 2.
Bendy has been a recurring silent stick figure since the first promotional trailer for Portal. It is used by Aperture Science as a representation of either test subjects or staff via the Investment Opportunity virals, and other informational screenings.
As of the Perpetual Testing Initiative DLC, community created test chambers are now shifted into an alternate universe whereby Cave Johnson still lives and resumes responsibility as CEO, and the construction of GLaDOS was abolished. In addition, this allows community created test chambers to be randomly chosen by the game for which of Cave's dialogues will be spoken through each player's testing queue.
Bendies also populate Pocket Universe Lab 08, the main location of The Lab. They also feature in the minigames Longbow, as armored moving targets, and Robot Repair, as the denizens of the Aperture Science Pocket Universe you accidentally disrupt.
In addition, the main goal of the third-party spin-off game Bridge Constructor Portal is to use the various tools provided to escort the Bendies to the exit of the test chamber, either on their own, or in a convoy.