Iron Rocks

Created by the Alien Mimy using old submarines Ironrocks was a highly armed submarine that was kept beneath the ocean and destroyed any ship unfortunate enough to be caught in it's line of fire. The Ultra Garrison was sent in to investigate the matter and launched two new submarines: The TDF HRs 1 and 2. After one of them escaped a whirlpool they spoted a Alien Mimy star-likesaucer under the water and was in persuit. The space ship managed to out manuver both submarines in the rocky coral and used special bubbles to jam communications. With the submarines incapable of doing anything Ironrocks was commanded by the Alien Mimy to surface and scare of the population of a local harbor town. Iron Rocks returned later that day to inflict catastrophic damage to the community and the Ultra Garrison was incapable of so much as scratching it. The situation grew worse when Dan was shot out of the sky with one of the Ultra Garrison's fighters, but after that the assault continued with the other fighter and managed to blow a hole in Iron Rocks. However, the Ultra Garrison was forced to stop due to analysis indicating that Ironrocks was actually an armed bomb. Upon the cease fire Iron Rocks remained stationary for the rest of the day and into the night until the Mimii Seijin called on it to fire on the town once again. The explosions managed to wake up Dan in his fighter and allowed him to turn into Ultraseven. After Alien Mimy taunted Ultraseven he had Ironrocks used it's chains to prevent Ultraseven from moving around, but it failed as the hero used the Energy Cartwheel to unchain himself. Ultraseven used the Emelium Ray to set Iron Rocks aflame and soon made it explode.

Trivia

 * While Iron Rocks did not return it inspired the underwater battleship Barracks in Ultraman 80's time.