Who doesn't love the Indiana Jones franchise (well, the first three at least)? And who doesn't love catching or hearing about sly movie Easter eggs? Well, you're in luck, because George Lucas and Steven Spielberg ensured to include plenty of cameos, sneaky references to their prior work (namely THX 1138 and the Star Wars franchise) and other clever visual nods in their classic Harrison Ford-starring adventure series in order to keep audiences on their toes. So well massaged into the four adventure flicks (yes, even the fourth one) are these Easter eggs that they've most likely made it past all but the keenest eyes, and as such if you did manage to spot any of them without assistance, give yourself a firm pat on the back. These blink-and-you'll-miss-it moments provide a little added value for film buffs and further reflect the series' playful tone. From crew cameos to well-hidden references to beloved Star Wars characters, hilariously (and surely intentionally so) fake animals, a nod of the fedora to the James Bond series and a couple of decidedly more demented hidden gems, here are 20 Indiana Jones Easter eggs you probably missed...