The first Ant-Man movie featured Darren Cross as the villain called Yellowjacket. However, fans of Marvel Comics may know that Cross, while a villain, was not Yellowjacket in the comics. That persona originated with the original Ant-Man, Hank Pym.
At one point during his superhero career, Pym lost his memory and took on a new personality, one that was in many ways the opposite of Pym’s usual personality. Where Pym was timid and bookish, this new personality was cocksure and bold. This personality also took on the new superhero persona of Yellowjacket, complete with a new costume.
It seems that Ant-Man and the Wasp almost got the Marvel Cinematic Universe version of Hank Pym, played by Michael Douglas, into that same Yellowjacket costume. Check out the concept art below to see what the MCU’s heroic Yellowjacket could have looked like.
This Yellowjacket costume ultimately did not make it into the film, though Hank did put on a different suit.