Kingsaurus III is an ancient dinosaur whose species survived the mass extinction at the end of the Cretaceous period, and now feasts on nuclear energy and Uranium-235. Appearing on a mountain, it was quickly confronted by MAT and shot down Hideki Go's MAT Arrow 2 with its highly radioactive U-235 beam. Go called upon Ultraman Jack and a fight ensued. Kingsaurus III's barrier quickly reflected all of Jack's attacks, even the Cinerama Shot, said to be ten times more powerful than the Wide Shot. After the blocking, Kingsaurus advanced; using his horn flashes to blind Jack while stabbing his knee and his waist. Finally, exhausted, Jack collapsed, and Kingsaurus III escaped through burrowing.
n the hospital, Go became horrified of the beast and later escaped the hospital to train himself to jump over Kingsaurus III's barrier and attack it. After training several times with his broken leg, he finally managed to learn the Meteor Kick and was ready to put it in action. Meanwhile, MAT received a telegram signaling that Kingsaurus III appeared at a nuclear power factory. Go soon followed and tried to jump over the beast's barrier. Failing, he called upon Ultraman.