I think Hellboy is sort of a prerequisite for anyone doing a project like this. Because I am already a HUGE Mike Mignola fan, not a lot of character study was needed for this one. Other great examples of Hellboy 'caricatures' that I've enjoyed recently include both by Vince Chui and also Julius Bulius .
The Hellboy without background is done exclusively by computer, including hand-made logo (that was harder than I thought it would be). The background for the other one includes inks and also pastels, which are great if you want to rub in some creepy effects.