Ant-Man and The Wasp Since he had the power to shrink to the size of an ant and the ability to control actual ants, super-scientist Hank Pym’s code name was inevitable. Along with his similarly shrinking sidekick-turned-girlfriend-turned-wife Janet “the Wasp” van Dyne, Pym helped found the Avengers and remained on the team for much of its existence, changing costumes and code names (see: Giant-Man, Goliath, Yellowjacket …).
Rick Jones In the comics, the five original Avengers were brought together by the teenage ham radio enthusiasts called the Teen Brigade (it was 1963). One of these was Jones, who would go on to become an honorary Avenger and a sort of free-floating sidekick who served time at the side of pretty much every Marvel hero at one point or another.
The Scarlet Witch Wanda Maximoff’s mutant super-powers are a bit ill-defined—they’re “magic,” essentially—but she and her super-speedster twin brother Quicksilver joined the Avengers alongside Hawkeye at a low point in the team’s history, and she was one of its longest-serving members. When it comes to film rights, though, she’s probably more closely tied to Fox’s X-Men franchise, since Magneto is her dad.
Vision This garishly clad (even by superhero standards) crying emo android was created by the villain Ultron to destroy the Avengers, but Vizh (as his friends call him) rebelled against his programming and ultimately joined the team, getting so comfortable he even married the Scarlet Witch. His powers include flying, eyebeams and the ability to phase through solid objects and feel genuine human emotions. Which he manifests by crying. A lot.