Arstron is one of the monsters that was woken up by the irregular weather patterns and shifts in the Earth’s crust. It is also the first monster that Ultraman Jack fights after fusing with Hideki Go. Arstron is adept at using his muscular frame and single horn to attack, and fires a Magma Ray from his mouth.

Arstron appeared in the Asagiri mountain range and attacked a nearby town. The MAT Arrow 1 and MAT Gyro attacked it from the sky but they could not stop its rampage. Arstron’s Magma Ray engulfed the town in flames.

Hideki realized where Arstron would appear again. He took a car from Tokyo and transformed into Ultraman Jack to stop the monster. Arstron used his strong tail and horn to attack Jack, but after Jack chopped off his horn, it was hit with a Spacium Beam to the head and defeated.