Hellboy is based on the comic book called Hellboy
the comic is actually really great, it is a reinvention of the old horror story comics and treats the whole deal tongue and cheek, the art is fantastic and the storytelling is really entertaining.
the comic creator/writer/artist Mike Mignola is really a genius, the way he illustrates, the stylstic nature of his lines, the emphasis on color evoking emotions etc. has really changed the face of comics.
ok i'm a geek, but seriously check it out, it's a fun read!