Hellboy Omnibus, Volume 1 by Mike Mignola

A gruff, red-skinned demon raised by human scientists and employed by a secret government bureau investigates a series of occult cases—ranging from Nazi occult plots and vengeful witches to ancient gods and folkloric monsters—while wrestling with questions of destiny, identity, and the fate of the world; the stories mix pulpy action, gothic horror, dark humor, and mythic atmosphere as the protagonist confronts both monstrous foes and the mysteries of his own origin.