A mainstay Pixar easter egg since their second short, the yellow ball with a blue stripe and red star has become an iconic image second only to Luxo Jr. As its less visually striking than the other recurring easter eggs, its inclusion is often overlooked, but for true Pixar aficionados its still a pleasure to find. Unlike some other entries on this list, its relatively easy to spot, but you may not have noticed it due to its plainness. When the toxicity of children is being explained to the scaring freshmen, one of the examples of a childs toy is the ball. Which makes a lot of sense; it appears in so many places over the world, plenty of kids must have them. In general the film did a good job in dealing with the toxicity problem - the monsters thinking kids are toxic when they actually arent - by keeping this element low key, but it was nice to see a major element from the first film brought together with a big Pixar in-joke.