Rhedosaurus is the name of the carnivorous man-eating lizard-like monster from the 1953 film The Beast From 20,000 Fathoms.
The Rhedosaurus in the film was one of the last surviving members of its species, awakened by a nuclear test in the Arctic. It made its way down the North American coast, destroying everything in its path and ending up in New York, its original home. Attempts to kill it were complicated by an ancient disease it carried; spilling its blood freed the plague, which was almost as deadly as the reptile itself. The Rhedosaurus was eventually killed at Coney Island when a radioactive isotope was shot into a wound on its neck, both fatally wounding it and also neutralizing the disease. The radiation also incinerated it, causing it to burn the island.