Pixar Ball

A yellow ball with a blue stripe and red star, known as the Luxo Ball (a.k.a. Pixar Ball), first appeared in the Luxo, Jr. short as a prop for Luxo, Jr. Since its debut, it has made numerous cameos in other Pixar films, most prominently in the Toy Story films.

Pixar

 * In Red's Dream, the design and color scheme of the ball appears on the floor of the circus ring.
 * In Toy Story, a ball rolls down the hallway of Andy's house as Sarge helps a "wounded" soldier to an indoor plant. A little later, one of Andy's friends bounce that ball up the stairs to Andy's room. Later, when Buzz proves to the toys that he can "fly," he bounces off that ball when he jumps off from Andy's bed.
 * In Toy Story 2, one ball appears in a TV commercial for Al's Toy Barn. Later, after the toys enter the toy store, one ball can be seen on the floor to the left, and a whole container of those balls can be seen to the left of the door when exiting.
 * The scene where Luxo, Sr. rolled the ball to Luxo. Jr in Luxo Jr. was also among the scenes that were flipped through by Hamm to find a commercial for Al's Toy Barn (which came after this scene).
 * In Boo's room in Monsters, Inc..
 * In the Dentist's waiting room in Finding Nemo.
 * One of Violet's toys in the alternate opening to The Incredibles.
 * One of Jack-Jack's toys in the short film Jack-Jack Attack.
 * Falling out of Presto's sleeve in Presto (at 2:34).
 * Under Alec Azam's ear in Presto (at 2:59).
 * On Sarge's sign when the neon night lights reboot in Cars.
 * On the floor of a neighborhood child's room in Up.
 * On one of Russell's merit badges in Up.
 * The design (yellow with a blue stripe and red star) appears on a tile on the side of Sunnyside Daycare in Toy Story 3.
 * Used as a volleyball by Chunk and the Jack-in-the-Box in the sandbox at Sunnyside Daycare in the end credits for Toy Story 3.
 * Part of the cargo Sidley crashes through in Cars 2.
 * In the Witch's cottage in Brave.
 * Among the pictures of "human kid toys" on the Scare Games walls in Monsters University.
 * Its pattern is stamped under the sink where Combat Carl and Jessie hide in Toy Story of Terror!.
 * Its pattern and name appear on the Battlesaurs boxes in Toy Story That Time Forgot.
 * During a flashback of young Riley playing tag with Bing Bong in Inside Out.
 * Floating past during the scene where Arlo and Spot get intoxicated from eating fermented fruit in The Good Dinosaur.
 * Steering wheel of quarantined truck in Finding Dory.
 * On the hood of one of the demolition derby cars in Cars 3.
 * In the scene where Dante has a scuffle with a spirit guide monkey at the rehearsal in Coco.
 * On Jack-Jack's crib design in Incredibles 2.

Advertising

 * As one of the marbles in the 1994 Levi's commercial "Woman Getting What She Wants" (0:10). This shot is also used briefly in Toy Story 2 as Rex skips through the TV channels.
 * In the double feature trailer for Toy Story and Toy Story 2 in Disney Digital 3-D.
 * Toy Story 3 posters and teasers (one teaser showed Bullseye rolling around on the ball and Slinky holding it as the "O" in "Toy").
 * In the 2011 State Farm commercial (at 0:14) on some of the "pet" trains.
 * Shorter Sky Broadband UK commercials promoting Toy Story That Time Forgot.
 * A giant version appeared in several promotional commercials for Toy Story Land. The latest 2 show it being pushed around by an equally large Slinky

Video games

 * Hidden in images in the membership page on The World of Cars Online website.
 * As a projectile, the loading screen and various other uses in Toy Story 3: The Video Game.
 * As a bonus in the Toy Story 3 mini games "Woody's Wild Adventure" and "Daycare Dash."
 * In the video game Kinect Rush: A Disney/Pixar Adventure.
 * As a badge in Merit Badge Mayhem.
 * In Ratatouille: The Video Game.
 * In the video game Disney INFINITY as one of the two-starter abilities for Woody, Buzz and Jessie. It acts exactly like the one in the Toy Story 3 video game.
 * In the video game Disney INFINITY: 3.0 as an obstacle in the Inside Out playset.
 * As a building in the Toy Story world of Disney Crossy Road.
 * As one of the non-playable Emoji of Disney Emoji Blitz.
 * As a Token needed for upgrading all Toy Story characters in Disney Magic Kingdoms.
 * On all the Pixar Family Build areas and packs in LEGO The Incredibles. A giant LEGO brick version of it is part of Luxo Jr.'s (called Junior) Pixar Family Build (which is unlocked after completing the other Pixar Family Builds; completing this one will unlock Junior himself) and the ball can be summoned by Junior.

Non-Pixar Disney appearances

 * The New Adventures of Winnie the Pooh in Christopher Robin's room
 * Lilo & Stitch
 * Mickey Mouse (in the episode "Dog Show")
 * Ralph Breaks the Internet

Non-Disney and Pixar appearances

 *  (green star)
 *  (white with yellow star)
 *  (red stripe and blue star)
 *  (red stripe and blue star)
 *  (green with orange star)
 *  (blue with green stripe and star)
 *  comic strips
 *  (as part of Bounce Baby's outfit)
 *  (as a sticker on April O'Neil's back shorts in some episodes)
 *  (as part of Bounce Baby's outfit)
 *  (as a sticker on April O'Neil's back shorts in some episodes)

Trivia

 * The Ball is also in the Toy Story Treat short "Oooh, Ball!", as well as a web short for Inside Out where Bing Bong plays with it.