He wasn't kidding when he said he'd be back. Although it's beginning to sound more like a threat than a promise at this point. No matter how many times you dip it in lava, cover it in molten metal or hire McG to direct it, The Terminator can never die. After four films, a theme park ride, countless books and comics and a TV show, the future still feels far away. Arnold Schwarzenegger finally returns as the noticeably saggier-looking synthetic robot killer in a couple of weeks time, when Terminator Genisys further messes up the already incomprehensible timeline of paradoxes the franchise is built on. This time, the T-800 is nice from the start, sent back even further to protect Sarah Connor before the events of the first film. The Terminator franchise has a rich mythology (stop laughing at the back), even if it's often difficult to parse. At this point the films don't so much innovate as find a way to twist and fit themselves between the strands of the labyrinthine plots, characters and themes of the previous films. And boy, do they like to remind you of the previous films. To be fair, a lot of the time sticking all those nods and nudges towards the older films is in keeping with the behaviour of James Cameron's original movies, which were equally full of cheeky winks to his other projects and the like. Here are twenty such Terminator Easter Eggs and references you must see.