Luxo is Pixar's mascot and the star of the 1986 short film of the same name. He is a small, light gray desk lamp (although he has sometimes looked more white than light gray) who loves to play with bouncy balls.
After having the same light bulb for over 20 years, WALL•E had to replace it for it when it went out, which can be seen in the trailer for WALL•E, replacing the standard bulb with a compact fluorescent. Luxo has been seen in every Pixar feature film since the first Toy Story.