A Terrible-Monster created by the remnants of the race of Extradimensional Being Yapool by gathering the souls and molecules of Terrible-Monsters previously defeated by Ultraman Ace and combining their best parts. Jumbo King is also called the “Terrible-Monster King”. Jumbo King attacks by firing flames and missiles from its mouth and beams from its eyes.

Jumbo King formed when the souls of Kunoichi Terrible-Monster Unitang, the Magma Terrible-Being Mazaronian, the Inferno Terrible-Monster Mazarius, and other monsters merged together in the sky. When the TAC Members fired missiles from the ground, Jumbo King returned fire with its own. Jumbo King was almost dragged away by TAC’s “Operation Lasso” using the TAC Falcon and two TAC Arrows. However, Jumbo King shook off the TAC Arrows’ rope and fell to the ground where it destroyed most of a city and disappeared.

Jumbo King reappeared the next morning at 8am. TAC failed to defeat Jumbo King with their new “Cell Division Missile”. Jumbo King destroyed the missile with a beam, and then attacked the city with fire and more missiles. Seiji Hokuto transformed into Ultraman Ace and Jumbo King tried to defeat him, but he was hit by Ace’s Metalium Beam and died after his head was severed by Ace’s Guillotine Chop.