Hellboy is a fictional character created by writer-artist Mike Mignola. The character first appeared in San Diego Comic-Con Comics 2, and has since appeared in various eponymous miniseries, one-shots and intercompany crossovers.
It's like Best and Worst of Villains, but for fictional heroes.
BTW, if anyone copies this (which might be likely since I've seen a few duplicate casts in categories like this one), this is the original.