The inside front cover has logo, credits, indicia, and frontispiece.
Mignola drew balloons and sound effects; Byrne lettered the dialogue with font based on his hand lettering. Neither is credited. // The Nazi officers are identified on the final story page, presented as a dossier on Project Ragna Rok. Manning's first name is revealed in a future storyline. Emma Cavendish's identity is revealed next issue. // Hellboy first appeared in a story in San Diego Comic-Con Comics (Dark Horse, 1992 series) #2 (August 1993), given away at the convention, and was seen in John Byrne's Next Men (Dark Horse, 1992 series) #21 (December 1993) as a fictional character a few months before this miniseries was released.
Monkeyman and O'Brien appear as a duo on the splash page only. Tiberius is not seen out of his suit until Chapter 2 and is named in Chapter 3. The characters' first published appearance, like Hellboy's, was in San Diego Comic-Con Comics (Dark Horse, 1992 series) #2 (August 1993), although the events of this story predate the duo's exploits in that issue.