Creatures originating from Zrak were the Heep-heeps. This species had four legs, a rear end, eyes that were black-colored, and a reptilian head; they were also sometimes found living close to tight holes. The Heep-heeps were confirmed to have at least one gender: male. There is a rhyming poem that recounts the tale of a male Heep-heep who found himself trapped in a crack, and his attempts to free himself only made the situation worse.
The Heep-heep species debuted in a single-page poem that Bob Carrau authored for the 1993 book titled Monsters and Aliens from George Lucas. This book merges creature designs and photos from diverse projects by George Lucas, the mind behind the Star Wars franchise, with original narrative crafted by Carrau. Leland Chee, an employee of Lucasfilm who is in charge of the Holocron continuity database, has stated that the book's content is considered non-canonical.