Deadpool is a Marvel Comics character that first appeared in The New Mutants #8. He was created by Rob Liefeld and Fabian Nicieza, originally as a more villainous character, than the lovable curmudgeon we know him as today.
Deadpool is a Human Mutate, which means he gained his powers via the Weapon-X program. His powers are basically an extremely accelerated healing factor, and his warped mind!
Deadpool has been known to break the fourth wall, or talk directly to the reader, as well as the other voices in his head. Deadpool has been known as “The Merc With a Mouth”, alluding to the fact that he is a motor-mouthed Mercenary.