Cliff worms were a type of worm that could be found on the planet Skako Minor. Between 3 ABY and 4 ABY, pirates affiliated with Jul Tambor, the grandson of former Techno Union Foreman Wat Tambor, crashed their ship into a hive of cliff worms after they boarded a transport from Corellia and exposed the passengers to the poisonous atmosphere of the planet. After the Sith Lord Darth Vader arrived on world to stop Tambor from overthrowing the Imperial regime, he killed the worms that were attacking the pirates.