Arstron is one of the monsters woken up by the irregular weather patterns and the 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 its muscular frame and single horn on its head to attack, and fires a Magma Ray from his mouth.

Arstron appears near the Asagiri Volcano and attacks a nearby town. The MAT Arrow 1 and MAT Gyro attack it from the sky but are unable to stop its rampage as its Magma Ray engulf the town in flames.

Hideki realizes where Arstron would appear again, taking a car from Tokyo to the area and transforming into Ultraman Jack to stop the monster. Arstron uses its strong tail and horn to attack Jack, but Jack chops off his horn and defeats it by a Spacium Beam to the head.