Hellboy is a fictional character, created by writer-artist Mike Mignola. Hellboy first appeared in San Diego Comic-Con Comics #2 (1993) and has since gone on to appear in a number of miniseries, one-shots and cross overs published by Dark Horse Comics.

Hellboy, also known by his true name Anung un Rama (the Beast of the Apocalypse),is a demon by the historical figure Grigori Rasputin and Nazi occultists. He was discovered by intervening Allied Forces, and 'adopted' by Professor Trevor Bruttenholm. As founder of the United States Bureau for Paranormal Research and Defense (BPRD), Bruttenholm raises Hellboy to combat occult and supernatural threats.

Hellboy is sensative about his outwardly demonic appearance. He's characterised by his red skin, tail, and oversized right hand made of stone and horns, which he files off (leaving circular stumps on his forehead) to make his appearance more human and normal.

It has been said that Hellboy smells of dry-roasted peanuts.

As an adult, Hellboy becomes the primary agent for the BPRD, alongside other human and 'not quite' human agents that include Kate Corrigan, a professor of folklore at New York University; Abe Sapien, an amphibian humanoid; Liz Sherman, a young pyrokinetic; Roger, an unusually large homunculus; Johann Krauss, the spirit of a medium kept in a containment suit; and Captain Ben Daimio, a special operations man with occult experiences, the latter two of which have not met Hellboy due to Hellboy's resignation from the Bureau.

Hellboy learns of his true origins during a visit to Bromwich Church. Hellboy learns he had been conceived 300 years previously by a witch named Catherine Tanner-Tremaine, and a demon Prince of Sheol.

Rather confusingly, Hellboy had not existed as a baby in the "real" world. The prince's "favorite son" was considered to be "a power waiting to be born." Hellboy's "mother" also had children: a nun and a priest who would later haunt the church, dying in an attempt to stop the demon from claiming Tanner-Tremaine on her deathbed.

Hellboy was granted "honorary human" status by the United Nations in 1952, and is known as the "world's greatest paranormal investigator". As such, he interacts regularly with humans, primarily law enforcement officials, the military, and various "scholars of the weird", most of whom are not presented as overtly reacting to his strange appearance.

This is one of the major differences between the comics and films, as in the comic books he is not living at the BRPD in secret, hidden from the general population.