Jailors and coin-counters, hamatulas guard the treasures of Hell, including their own. They are miserly and bloodthirsty by turns, and, as F. Wesley Schneider notes in Princes of Darkness, loath to be summoned by mortals. Barbed devils don’t have to necessarily be outsiders, either—fans of darker fairy tales and films like Pan’s Labyrinth might easily adapt barbed devils for their purposes.
Elaborate dungeon complexes sometimes pierce the barriers between the planes. More than one party has attempted to leave a dungeon only to come upon a plainly appointed room—surely not present a moment before—with two doors, each guarded by a barbed devil. One door leads up and out to safety, the other to the devils’ personal treasure hordes and Hell. Of course, the hamatulas do not intend to let adventurers through either.
A barbed devil is proud of his collection of grigs, pixies, and other winged sprites, kept suspended alive in magical cases with his very own spines. Now he plans to auction off his collection. The Queen of Zephyrs, a nymph air elementalist, wants the captive fey of her court freed, especially her favorite pixie cavalier.
Speaking of fey, barbed devils have analogs in the faerie realms. Needlejacks are appallingly thorny, powerful fey as like to torment their kindred as they are mortals. The unobservant might mistake one for a hamatula, but needlejacks have fey traits, tend toward Neutral Evil, and replace hamatulas’ unholy, fire-related, and summoning spell-like abilities with ones devoted to illusion, predation, and pure pain.
—Pathfinder Bestiary 72