The Thing is the superhero identity of Benjamin "Ben" Grimm. The Thing's super powers include super strength, durability, stamina and resistance to physical injury.
His superpowers were gained from exposure to the cosmic rays in space. He is the only member of the Fantastic Four to suffer a physical change to their appearance after being exposed to the cosmic rays.
The Thing has had some difficulty fitting in with the rest of the team and partly blames Reed Richards for his appearance. Like all other members of the Fantastic Four his identity is publicly known to the world.