Perhaps the most plain lovable B.P.R.D. agent and also one of the most tragic, Roger is, in a manner of speaking, the only enhanced agent character to die and for that death to be truly permanent. Of course you have to be alive first in order to die and the fact that the former is a matter for debate is the real tragedy of Roger. A homunculus is a human creature made by an alchemist from mud, blood and herbs; usually they are miniature in size, so Roger is something of a giant among his kind (although not so much as his truly giant brother). Typically dressed in nothing but a 2x4 with a metal ring in it across his crotch, Roger represented a force of cheerfully naive, unworldly good spirit. Brought to life by Liz's pyrokinetic touch during the Wake the Devil arc, Roger was only supposed to be a single-story character, but Mignola realised his appeal and brought him back. His mistreatment by the BPRD hierarchy (they place a bomb inside him) is what makes Hellboy leave the Bureau, showing just how important his life is to some. After his death at the hands of the Black Flame, the attempt to resurrect Roger and the acceptance of leaving him "dead" is easily one of the best tearjerking moments in the Hellboy universe.
4. Abe Sapien
Although introduced as the primary supporting character in the early Hellboy stories, amphibious Abraham Sapien is so much more than a simple sidekick. While his story may have originated with Hellboy taking him under his wing, rescuing him from the experiments in the nightmarish labs of the B.P.R.D. and taking him out on his first missions, Abe becomes one of the most independent, capable characters in the Hellboy universe. Even in the first published story Seed of Destruction, it is Abe and not Hellboy that defeats the villainous Rasputin. Abe's aquatic abilities make for some of the most visually impressive comics with a huge variety of artists giving stories that reek of damp and darkness. Gradually that darkness has taken over the character more and more, isolating him increasingly from the rest of the B.P.R.D. team as he seeks to understand who he really is and discovers that identity might not be the most desirable one. From the suggestion that his amphibious form may be related to the frog monsters, to his history as ambitious Victorian mystic Langdon Everett Caul, Abe's story is an increasingly tragic one, culminating in the story of Caul's drowned wife and Abe's chance at a creepy simulation of "normality".
