Cap vs Iron Man? Magic sorcerers? Hulk and Thor teaming up? Whatever awesome things James Gunn has in store for Guardians Vol. 2? Josh Brolin as a big purple guy who now does more than sit in a chair? Oh, and Spider-Man?! Looks like Marvel's really going all in with Phase 3 of their Cinematic Universe; if the first run of movies was building to The Avengers and the second dealt with character progression (kinda), this third batch is all about making the standalone movies feel as essential and epic as the ones with Earth's Mightiest Heroes in the title. Which is all very awesome, although you have to hope in all this fun they don't forget one of the most enjoyable parts of the movies thus far. I'm talking, obviously, about easter eggs - the little hidden details and references that Marvel have become experts at, teasing the future, honouring the comics and generally giving the fans a reason to rewatch their movies to box office dominance. It's always fun to go into a new film and look for what surprises are snuck in there, but going into Phase 3 there's some easter eggs that are almost required; nods to behind-the-scenes issues, acknowledgement of key influences or, in certain cases, the clearing up of major fan conclusion. Here are the twelve biggest.