A Terrible-Monster created by Yapool, the extradimentional being, by combining a space monster with a moth. Doragory is violent and savage by nature. It attacks with rocket missles fired from its hands and flames emitted from its mouth. It has super strength and can easily tear other kaiju to pieces.

Doragory appears at the TAC Base, where they are developing the Maria 1 missile to destroy Goran, the ominous planet, and destroys the base with its flames. Ultraman Ace arrives and Doragory attacks him with flames and punches, but Ace uses his Ace Barrier, teleporting Doragory to the edge of Earth’s atmosphere and trapping it there.

After breaking free of the trap, Doragory reappears with Alien Metron Jr. to attack Ace. They are joined by Muruchi II, the giant fish monster, but Muruchi tackles Doragory by mistake and gets torn apart by Doragory's super strength.

After being trapped again by Ace Barrier, Doragory appears for a third time with Metron Jr. Their combined attacks overpower Ace, but Ace defeats Doragory with the Ace Blade and the Metalium Beam.