Several years ago, Jason Rekulak, the publisher of Quirk Books, was shopping for furniture with his wife at an Ikea in Philadelphia when he became lost in the mazelike showroom.

Mr. Rekulak, who has a freakishly fertile imagination, promptly came up with an idea for a parody novel titled “Horrorstör,” about a haunted Scandinavian furniture superstore, where employees are trapped overnight with paranormal forces. He hired a writer, Grady Hendrix, to flesh out the story, and packaged the book like a glossy Ikea catalog. It’s now in development as a television series.

At Quirk, a small independent publishing house in Philadelphia, the restless Mr. Rekulak has produced a string of bizarre best sellers. He helped engineer unlikely blockbusters like Seth Grahame-Smith’s “Pride and Prejudice and Zombies,” and has nurtured fledgling writers who turned into breakout stars, including Ben H. Winters and Ransom Riggs, whose creepy young-adult novel “Miss Peregrine’s Home for Peculiar Children” and its sequels have sold more than nine million copies.