For Pixar fans with an eagle eye, A113 may be a familiar sight, but have you wondered why animators put it there? A113 was the classroom number used by character animation students at the California Institute of the Arts. Many of its alumni (including Pixar staff) have used the number in their professional works. It is said to appear in some way, shape, or form in every Pixar film. However, none have been found in Monsters, Inc. In addition to Pixar films, this running gag also appeared in some non-Pixar films, such as Lilo & Stitch, The Avengers, Rise of the Planet of the Apes, Mission: Impossible – Ghost Protocol, etc. Continue reading for more sightings.