 All these groups have varying lineups; the Avengers have included Marvel's major heroes as members at one time or another.The X-Men are a team of mutants led by Professor X and include many of Marvel's most popular characters, such as Wolverine and others.The Fantastic Four are viewed as "Marvel's First Family" of superheroes, usually consisting of Mister Fantastic, the Invisible Woman, the Human Torch and the Thing, as well as siblings Franklin and Valeria Richards.