Ant-Man and the Wasp: Quantumania is wrapped in secrecy as a pivotal chapter of the Marvel Cinematic Universe Phase 4 storyline. Quantumania will officially introduce the next MCU big bad in Kang the Conqueror (Jonathan Majors), but a new rumor suggests that there could be another Marvel villain invovled in Ant-Man 3 – and that a former MCU star could actually be brought back in that new villain role. Obviously that's just hearsay, but this new rumor does indeed coincide with an earlier spoiler that an actual star of Ant-Man and the Wasp: Quantumania let slip, early on in production!
(WARNING: Potential Ant-Man and the Wasp SPOILERS Follow!)
The new rumor about Ant-Man and the Wasp: Quantumania says that the villain of the first Ant-Man movie, Darren Cross (actor Corey Stoll) will be making a return to the MCU as M.O.D.O.K. in Ant-Man 3. GWW has updated earlier rumors of Jim Carey being MODOK in the MCU to say that it will in fact be Stoll who plays that villain character. Ant-Man franchise star Evangeline Lily previously spoiled the fact that Corey Stoll was going to be in Ant-Man 3, early on in production. Lily accidentally tagged Stoll in an Instagram post celebrating production on Quantumania with all her fellow cast members. Oops.
At the end of Ant-Man, Darren Cross donned the Yellowjacket armor suit and did battle with Scott Lang's Ant-Man – a fight that ended with Darren being seemingly imploded and sucked into the Quantum Realm. What actually happened to Cross is anyone's guess; if Scott and the Pyms can all make it back from the Quantum Realm Darren could too – but after what his body went through, MODOK may be the only form he can still exist in.
If you don't know, "M.O.D.O.K." (or Mental/Mobile/Mechanized Organism Designed Only for Killing) is a Marvel Comics villain who is attached to the A.I.M. (Advanced Idea Mechanics) organization. MODOK was a man who undergoes radical mutation and experimentation designed to create a super-intelligence; the process succeeds at the cost of the man's head being freakishly enlarged and his body stunted, requiring him to be cybernetically fitted for a hoverchair to move around.
Clearly, it wouldn't be hard for the MCU to remix the MODOK origin story into one that sees Darren Cross make it out of the Quantum Realm (or get transformed while still in it) having both gained vast knowledge while his body is wrecked. How this version of MODOK would fit inot the larger MCU is still anyone's guess (Kang's servant? A.I.M.'s weapon? HIs own mastermind schemes?).
Ant-Man and the Wasp: Quantumania will be in theaters on