If you know anything at all about Pixar Animation Studios, you probably know that they like to insert easter eggs into their movies.

It's very common to see a reference to one Pixar movie while watching a different one. The Pizza Planet truck, for example, which was part of an important plot point in the original Toy Story, has become notorious for popping up in nearly every movie Pixar puts out.

Some fans have made a game out of spotting the Pizza Planet truck in each new movie that Pixar releases. It's sort of like Where's Waldo? on the big screen.

What you may not know is just how many of these easter eggs can be found throughout Pixar's movies. An official Disney blog called "Oh My Disney" has put together a nifty little montage video that shows off several of these cross-references in movies like Monsters Inc., Brave, Cars, Ratatouille, WALL-E and more.

While not comprehensive, it shows a good sampling of Pixar's cleverness.

What other easter eggs have you found in Pixar's movies?

Pixar's next blockbuster, Inside Out, arrives in theaters on June 16, 2015. Keep your eyes peeled while watching; you never know when or where one of the animation company's previous characters might show up. With Inside Out taking place almost entirely inside the mind and imagination of a child, there are plenty of places animators could have inserted easter eggs.

Just look at this still from the movie. How many potential easter egg spots do you see?

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