The Weta-rex's scientific name is Deinacrida rex. The name "Weta-rex" comes from the weta, a group of about 70 insect species native to New Zealand, of which the Weta-rex resembles a gigantic version.
Countless Weta-rexes swarmed the crew of the Venture after King Kong threw the log bridge they were crossing into the chasm below. Several of the creatures began to swarm Jack Driscoll, crawling all over his body, forcing Jimmy to try and shoot them off with a machine gun. As more waves of Weta-rexes and other giant insects converged on the surviving crew members, Bruce Baxter swung into the chasm on a vine, mowing down the creatures with his machine gun and forcing the rest to retreat.
Weta-rexes are vicious predators that hunt in packs. They use their overwhelming numbers to bring down prey much larger than themselves. Their mouths are equipped with shearing mandibles capable of shredding the skin of various dinosaurs living on Skull Island.
- The Weta-rex is based on the real-life weta insects native to New Zealand, the native country of King Kong director Peter Jackson. The New Zealand-based special effects company Weta Workshop, who provided the creature effects for Jackson's King Kong and collaborated on Legendary Pictures' Godzilla, is also named after the weta.