Hero with Y

• yondu

  Valid—Marvel antihero; Ravager who aids the Guardians.

• Yandroth

  Marvel sorcerer villain turned uneasy hero

• Yogi Bear
• Yoda

  Valid—Jedi Master hero from Star Wars.

• yellowjacket

  Valid—Marvel hero alias; Hank Pym used it.

The words in the list Hero with Y come from players of the word game Categories game.