Songbird

Melissa Gold, a.k.a. Songbird, (voiced by Jennifer Hale) is a superheroine from Marvel Comics. She appears in Avengers Assemble. She was formerly the supervillain, Screaming Mimi, and was a member of the Masters of Evil. However, as Songbird, she posed as, and later genuinely became, a superhero, and was a member of the Thunderbolts (the Masters all posing as a hero team, but became one in earnest).

She later temporarily became a member of the government-allied Mighty Avengers.