There are four core individuals who make up the Fantastic Four, having gained superpowers after exposure to cosmic rays during a scientific mission to outer space. Mr. Fantastic (Reed Richards) is a scientific genius and the leader of the group who can stretch his body into incredible lengths and shapes. The Invisible Woman (Susan "Sue" Storm) is Reed's wife; she can render herself invisible and project powerful force fields. The Human Torch (Johnny Storm) is Sue's younger brother, who can generate flames, surround himself with them and fly. The final member is the monster-like Thing (Ben Grimm), their grumpy but benevolent friend, who possesses superhuman strength and endurance.
Since the original four's first appearance, the Fantastic Four have been more than just a somewhat dysfunctional yet loving family. Breaking traditional "superhero" rules of decorum, they would squabble and hold grudges both deep and petty, and eschew anonymity or secret identities in favor of celebrity status.
The Fantastic Four have at times included many other individuals in their ranks, the original members taking leaves of absence for various reasons. Members have included She-Hulk, Power Man, Medusa, Crystal, Black Panther, Storm, Doctor Strange, Spiderman and Wolverine