Continuing the steady stream of production sketches, this one is from Mike Mignola, with Hellboy as he was toward the end of the first movie:
Mignola Devil (Hellboy Icon, Death's House)
Guillermo del Toro: Inside the Angel of Death lair - laid out in a fresco on the floor - there is a game board representing Hellboy's origin and destiny. Mike Mignola based his designs for this on old Zodiac illustrations. This particular one shows Hellboy in his "Apocalyptic" incarnation at the end of days.