Ultraman: S1 E29 - Challenge To The Underground Ultraman
A golden monster Goldon showed up at Mt. Ota gold mine, which has the largest amount of reserves in Japan. In order to repel Goldon which freely moves back and forth between the ground and the ground, Muramatsu and Ide used a prototype Subterrene Vellucidar and succeeded in defeating Goldon. However, Vellucidar broke down during the battle, and at that time, another Goldon appeared!