First introduced during an Abe Sapien solo adventure and later given his own series, Witchfinder, Victorian paranormal investigator and adventurer Edward Grey's story is a spin-off of a spin-off. Grey has barely appeared in the original Hellboy comic (bar a brief cameo as a hooded and masked figure), but his story appeals by broadening the Hellboy universe to show supernatural adventures across earlier time periods. A mortal man (at least initially) with just a bit of magical knowledge and 19th century technology, Agent to the Queen of England and private occult detective Grey still manages to take on the forces of the paranormal with every bit the same capability as the modern BPRD. Many of his adventures involve Grey coming up against sinister secret society the Heliopic Brotherhood of Ra, tying him into the early stories of both Memnan Saa and Abe. Like many other characters in the Hellboy universe, Grey has a tragic undeath: dragged to hell, torn to pieces, and then put back together, which accounts for his current masked appearance. He retains, however, a great deal of faith in Hellboy's moral choices and is sure to appear in future installments.
10. Professor Trevor Bruttenholm
He may be the genetic offspring of the demon Azzael (presuming that demons have genes) and have been brought into the world by Rasputin, but there is only one man that Hellboy can really call "father": Trevor Bruttenholm. Bruttenholm may have died barely ten pages into the first Hellboy story, but he casts a long shadow over the rest of his adopted son's adventures and choices. No wonder the film, where John Hurt was perfectly cast as Bruttenholm, chose to give him more time and the comics later explored stories of his earlier life. In the 1940s BPRD series, we get to see Bruttenholm matching his not inconsiderable wits against strange and supernatural creatures far more powerful than him, while the Hellboy comics set in the 40s, 50s and 60s show quite why he made such a good surrogate father. As the film makes explicit, it is Bruttenholm's role as the moral core of Hellboy's world that have made Hellboy a hero rather than a destroyer of worlds, the triumph of nurture over nature.
