The brand name is a made-up noun, like Kodak or Xerox, and was originally invented to name the Pixar Image Computer. Coincidentally, 1986 was also when Steve Jobs hired Paul Rand to design the NeXT logo.
One of the first projects Pixar completed was the short film “Luxo Jr.” It was John Lasseter’s official directorial debut, and became the first 3D computer animated film to be nominated for an Oscar, in the category of Best Short Film (Animated).
With that, “Luxo Jr.” became an integral part of the Pixar branding, serving as the mascot and appearing in Pixar’s production logo at the beginning and end of each film. You’ll likely know what happens if you’ve seen a Pixar film — Luxo Jr. hops in from the right, stops beside the letter ‘I’ of PIXAR, and jumps on it until the letter’s flattened, just how the ball was falttened in the original Luxo Jr. film.
The logo animation has differed slightly across the Pixar film catalogue. In Pixar’s WALL-E (2008), for example, the film’s lead character makes an appearance, changing Luxo Jr.’s light bulb.
In other films, everything in the sequence — the bouncing, the fade out, the light turning off — is timed to match whatever music’s playing at the time of the start or end credits. Different variations are listed on the Pixar Wiki.
According to Lee Unkrich, the animation for the Pixar logo was done by Pete Docter, director of films such as Monsters Inc., Inside Out, and Up.
The logo was later reanimated, presumably for higher definition, but whoever did the work simply mirrored what Pete had already created. I introduced my 4-year-old to Pixar last weekend when we watched Up. She loved it, unsurprisingly. One of Pixar’s best.