Subtitle: Ancient Monster (古代怪獣 Kodai Kaijū?).
The Return Of Ultraman
His height is around 45 Meters tall. He weighs around 15,000 Tons. He is the insinctive rival of the monster Gudon.
MAT was called in when an ancient egg was dug up in a construction site, but it proved nearly indestructible to MAT's efforts and yet a heartbeat was heard within the ancient object. While MAT was preoccupied with the recently discovered Gudon, the egg was buried once more by the construction crew. Shortly after, the egg increased into near kaiju size and erupted from underground in the middle of the Tokyo. After doing some research, MAT soon discovered that the egg was that of Twin Tail, the instinctive rival of Gudon, which explained why Gudon had emerged in the first place.
Eventually, Twin Tail hatched from his egg and began to rampage in the city. Goh transformed into Ultraman Jack to confront the monster, and the two had a long and difficult fight. Suddenly Gudon emerged from underground, confronting Jack and his archrival. His color timer already blinking and sandwiched between two bitter ancient enemies, The two monsters were too much for Jack to handle, who had no choice but to retreat. With Jack out of the way, Twin Tail and Gudon collided and resumed their blood feud in a vicious fashion. The victor however was never solved as the two monsters separated (unexplainedly) for the time being.
After viewing the damage caused by the monsters, the military threatened to unleash a 'mini' H-bomb to slay the two monsters. Knowing many innocent people would perish if that happened, MAT decided to try one last attack on Twin Tail and Gudon. Preparing jeeps, armed with nothing but bazookas, MAT waited for the two prehistoric beasts to appear. Twin Tail appeared first from beneath the Earth and MAT launched their first attack, aiming for the prehistoric beast’s eyes and blowing out one of Twin Tail’s eye before Gudon erupted from the ground. Ultraman Jack soon returned and subdued Twin Tail, allowing MAT to blow out the monster’s other eye. This time, Jack stepped back to allow Gudon and Twin Tail to fight it out. Twin Tail finally met his demise after receiving fatal wounds by Gudon.
This Monster reappeared in the series Ultraman Mebius.
Released into the sea by Bogal as an orb, GUYS eventually found the orb in the sea. Once they dove into the sea to find it, Bogal cracked open the orb and from it released Twin Tail. Mirai quickly turned into Ultraman Mebius, but Twin Tail was too agile in the water, and was winning. But GUYS soon discovered Twin Tail's weakness: The two, glowing blue spots on its body. They attacked it, which greaty injured the monster, giving Mebius the instant he needed to destroy Twin Tail with his Mebium Beam.
Later on, another Twin Tail appeared and was seen fighting another Gudon, with no one knowing how or why they were alive and fighting. Their fight was halted by Bogal, who beat both monsters into submission until eating them.
Sometime later, GUYS was chosen to test out new arrivals of Capsule Monsters. One suggestion was Twin Tail, but was turned down due to his limited capabilities on land.
Ultra Galaxy Mega Monster Battle
This Monster reappeared in the series Ultra Galaxy Mega Monster Battle.
A Twin Tail appeared one night and ambushed Rei, who summoned Litra to do battle. With the combined efforts of Litra and Rei's weapons, Twin Tail was quickly finished off by Rei's gunfire and Litra's fireballs.
Mega Monster Battle: Ultra Galaxy
This Monster reappeared in the movie Mega Monster Battle: Ultra Galaxy
Twin Tail is one of Ultraman Belial's 100 Monster Army. He was killed by Ultraman in the final battle.