The MUTO (Massive Unidentified Terrestrial Organism) are prehistoric parasitic kaiju that existed during the Permian era alongside Godzilla's species. Two individuals are known to have survived the Permian Extinction event and lay dormant until 2014. The Female MUTO first awoke within Yucca Mountain after hearing mating calls from the Male MUTO, and followed these calls from Las Vegas to San Francisco, where it dug a nest after meeting up with the male.