Marvel movies would not be complete without a cameo by creator and writer Stan Lee -- whether as a hot dog vendor, a mental ward patient, a security guard or just a random old guy.

At 91, he seems unstoppable as he confirms his cameo for the next Avengers installment, "Age of Ultron." A comic legend himself, Stan Lee even joked that DC Comics could use his help for its next big film, "Batman V Superman: Dawn of Justice," saying it would draw viewers' attention and they would have to go to the theaters just to see if he would really do a cameo, Design & Trend reported. This could probably make DC a lot of money, he added.

But fans should probably not expect to see S.H.I.E.L.D. agent Phil Coulson (Clark Gregg) in the new Avengers movie. Coulson's death in the first film was a crucial point in the story. However, he may appear in the third Avengers, where Marvel is planning to reveal that he is alive and heading up a new version of S.H.I.E.L.D., according to ComicBook.com.

While fans know they will see Scarlet Witch and QuickSilver in Avengers 2, some speculate that another superhero may be joining the team, as She-Hulk is being considered. Creators still have time to include her -- and other heroes, for that matter.

She-Hulk, or Jen Walters, is a skilled lawyer and cousin to Bruce Banner. When she was badly wounded, Bruce was left with no choice but to transfuse his blood into her body to save her life, infecting her with his transforming condition. However, the effect in her is milder, allowing her to keep her personality despite the transformation.

"Avengers: Age of Ultron," directed by Joss Whedon, will be released in U.S. theaters on May 1.