A weapon of the Underground People, Telesdon was unleashed to terrorize Tokyo on the surface world, as well as distract the Science Patrol from the Underground People's real plan. The Underground People had captured and attempted to hypnotize Shin Hayata into using Ultraman as their own weapon. However, they underestimated Ultraman's power, as Ultraman's light and energy blinded and killed the Underground People and Ultraman quickly escaped to the surface to fight Telesdon. While Telesdon tried his best, he was of little match for the hero and was beaten to death and finished by Ultraman's Dropped Rock.