Bogun first appeared in Ultraman: Towards the Future, episode 1 "Signs of Life".
The first of many organisms to be mutated from Gudis' virus, Bogun changed his appearence from that of a tadpole to a gigantic brute rampaging through the United States. The UMA was sent to destroy it, but only succeeded in annoying Bogun. Jack was hesitant to kill the beast since it was being driven by the Gudis virus, and not acting on its natural instincts, but he eventually used the Delta-Plasma pendant to turn into Ultraman Great, and fight Bogun himself, to prevent further loss of human life. As the two clashed, Great seemed to have the upper hand, until Bogun used his poison gas. However, the Ultra Warrior persevered and eventually used the Burning Plasma to vaporize Bogun in a fiery cloud.