Flash Thompson

Flash Thompson has already appeared in both previous Spider-Man franchises, but he's always been a one-note supporting character who's disappeared after the first installment. If done right, however, he could be one of the most important characters in the franchise. Since Peter's going back to high school in 2017, that means that Flash - the run-of-the-mill jock and bully - is likely just around the corner. He wouldn't just fit well into the John Hughes-esque soap opera side of the story, either. His destiny as Venom could prove invaluable to the franchise as a whole. After graduating high school, Flash enlists in the military and eventually loses his legs in combat. He then goes on to become Agent Venom, donning the famous symbiote for 48 hours at a time (in order to evade letting it take control of him) and embarking on dangerous missions for the military. Agent Venom would be a great way to introduce Venom back into the cinematic fold in a post-Spider-Man 3 world, and could sidestep Feige's "villains we haven't seen yet" rule via a technicality.