If you've ever been to a Marvel movie with someone who's into the source material, then chances are pretty good you've had your ear bent toward discovering all the references and in-jokes hidden in the script and the backgrounds of scenes that you would have missed had you not been so lucky as to have a friend acting as your very own personal Easter Egg hunter. Those creative types at Marvel Studios really know how to pack 'em in, and now, with their very own TV show and regular air time most weeks, they can cram even more nods, winks and even a few wince-inducing screams of "HEY, JUST REMEMBER THAT WE MAKE IRON MAN TOO, OKAY?" Some of these seem innocuous and pointless enough - really just there to make hardcore fans smirk once in a while - but others are potential clues as to the future of the series and possibly even the larger Marvel Cinematic Universe. It seems wrong to make you go hunting for all of them yourself, so we've collected 20 of the best and weirdest for your viewing pleasure all in one place.
20. The Cube/Marvel Boy
In the episode Providence, while trying to compile a list of which SHIELD facilities are still active after HYDRAs big reveal, Phil Coulson mentions one called The Cube thats still functioning. Comics fans will recognise this base as the one in which Kree supervillain/anti-hero/lover of close harmony 60s girl groups Marvel Boy was held captive after attacking the US government. During Norman Osborns tenure as the director of the Thunderbolts (a team comprised mainly of ex- or current villains), The Cube served as the teams home base, and became home to Osborns fake Avengers (including Marvel Boy among their number) when he dismantled SHIELD and became head of its replacement, HAMMER. The thought of Marvel Boy being hidden away in his own private prison is pretty exciting, and if the theory that Coulsons blue alien is Kree is true then it lends credence to the theory that we might meet the arrogant but entertaining young spaceman at some point down the line.