PHILADELPHIA — It's been two decades since Mike Mignola created a horned, red-hued devilish beast with a penchant for cigars and a big gun.

Since that first appearance in the pages of Dark Horse Comics' “San Diego Comic-Con Comics” No. 2, Hellboy has become a top-seller for the publisher, transformed into animation and spawned a pair of films starring Ron Perlman as Hellboy.

Not to mention a bevy of comic book titles anthologized and reprinted time after time.

“I didn't think it would last four issues,” Mignola told The Associated Press Thursday. “That was my goal. Do four issues then hope I can find another job.”

It's lasted, he conceded, though the character is in the midst of an impossibly difficult adventure: being dead.

Mignola said he's working to figure out what happens to his creation, who died in 2011 and — for now — is in hell.

“How do you end a book where you've already killed the guy off?” he asked. “It's going someplace and there's certain things that have to get done, but as far where it's going, I can't really say.... It's building to a certain kind of climax.”

While that climax builds, Milwaukie, Ore.-based Dark Horse is marking the 20th anniversary with international events March 22 in Portland, Los Angeles, London, Buenos Aires and Skokie, Ill., featuring artists and others involved in the various Hellboy stories it has published.

Scott Allie, Dark Horse's editor-in-chief, said the company's involvement with Mignola and Hellboy is what has helped define it as a publisher.

“Every creative person or company aspires to be a part of something with such cultural relevance across so many media that continues to earn awards, rave reviews, and reach new readers,” he said. “Dark Horse defines itself by our creative integrity, and there's no better example than Hellboy, where we've worked with one of the geniuses of the medium for 20 years, building Mignola's world around these characters. Dark Horse is very proud, and happy if we are in part defined, by this one.”

Mignola said Hellboy's appeal, while hard to pinpoint, is because of the way he has written the character.

“Even though it deals with monsters and the supernatural, I tried to write that character like a regular person,” he said.