Marvel Studios

Before Marvel Studios came along, Easter eggs -- or small lines or visual cues that are included in movies as nods to fans in the know -- were few and unimportant. Stan Lee got his "Spider-Man" cameos, Wolverine joked that his suit wasn't "yellow spandex," and Lou Ferrigno was seen briefly in "Hulk."

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But with the advent of the Marvel Cinematic Universe, starting with "Iron Man" all the way through its newest release, "Guardians of the Galaxy," Easter eggs have become an art. Sure, sometimes they're still similar to the old ones -- after all, Stan Lee still has had cameos in every MCU movie so far -- but Marvel was the first studio to really ask its fans to rewatch, slow down, and magnify its movies to find all the secrets within, secrets which could be integral to the plot of future movies.

Captain America's shield can be found in the first "Iron Man," which at the time seemed like a throwaway, until we realized that Tony Stark's dad was integral in the hero's creation. A map behind Tony in "Iron Man 2" shows the location of each Avenger, with some still to come. The Infinity Gauntlet, sure to play a huge role in upcoming "Avengers" movies, is seen briefly in Odin's Trophy Room in "Thor," along with a number of other objects which might foreshadow future storylines.

The level of detail Marvel has lavished on its movies is insane, so we decided to try to make it a little more palatable, with this video, narrated by MTV News' Josh Horowitz, of every Easter egg in the Marvel Cinematic Universe* to guide you through the jokes, fun facts, and hidden plot secrets.

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And honestly, the universe is just so expansive that we probably missed some, so let us know if you noticed any in the comments!

*Note: This does not include "Captain America: The Winter Soldier" or "Guardians of the Galaxy," which are not available at this time.