Phirasaurus is a kaijin of the Shocker organization with the characteristics of a Pyrasaurus that once lived in the hinterlands of South America and an antagonist in Kamen Rider.
He is voiced by Yatsu Isao. His human form is portrayed by Taku Fujiki.
History[]
Phirasaurus was created from pro-wrestler Noboru Kusaka after he was kidnapped and remodeled by the Shocker organization. Initially, another human was chosen to be remodeled, but this one could not withstand the toxicity of the death fog and died during an experiment on a route bus, leading them to abduct Kusaka after he was judged to be the most suitable person by Shocker's computer.
Phirasaurus was then put through a series of performance tests by executives Maya and Hurricane Joe to demonstrate its toughness. For its final test, it was sent to attack Hayato Ichimonji while he was practicing at the motocross practice field. He fought Hayato after he transformed Kamen Rider 2, and defeated Kamen Rider 2 by sending him into a nearby pond with an Ultra Kick.
Phirasaurus would later reappear in the ring as a masked wrestler, Satan Mask. Following a match, he tried to kill his younger brother, Kiyoshi Kusaka, who was about to discover his true identity, but was stopped by Kamen Rider 2. After a series of wins, Satan Mask entered his title match which representatives of Japan's political economy were expected to attend. Phirasaurus was ordered to kill them with the Fog of Death, but before he could Kamen Rider 2 arrived at the venue just before the match started. Kamen Rider 2 then challenged Satan Mask and called on the audience to escape
While Tachibana and others helped the audience evacuate, Satan Mask fought Kamen Rider 2 in the ring and revealed his true form. He attempted to use his fog of death on Kamen Rider 2, but it was already used up. Phirasaurus then resorted to using its Ultra Punch in an attempt to defeat the Rider, but Kamen Rider 2 defeated it with a Rider Kick and restored Noboru Kusaka to normal.
Powers and Abilities[]
Phirasaurus fights with a strong body that can withstand direct hits from rockets and a deadly poisonous gas "death fog" that can even defeat giant dinosaurs.

