Zazahn

 Zazahn (ザザーン - Zazān) is a monster that appeeared in the TV series, The Return of Ultraman.

Subtitle: Sludge Monster (ヘドロ怪獣 - Hedoro kaijū)

Powers/Abilities:

 * Adept Swimmer : Being completely composed of seaweed, Zazahn is fully capable even if underwater.

History:
Zazahn was one of two aquatic monsters that rose from the depths of the ocean along with Takkong. The two monsters battled at once, smashing through nearby structures in Tokyo Bay. During the midst of their fight, a young man known as Hideki Goh was killed while he was rescuing lives from the two monsters' destruction. Zazahn and Takkong continued their titanic war, until finally the battle ended with Zazahn being beaten to death by Takkong.

Trivia

 * Suit Actor: Eiichi Kikuchi.
 * Zazahn's debut was coincidentally at the same time of the release of the Toho film, Godzilla vs. Hedorah. This is most likely done to propagate the serious pollution crisis that was plagueing Japan at the time of the episode's airing.
 * Although not physically seen, Zazahn is one of the monsters that makes up Beryudora's Left Arm in Mega Monster Battle: Ultra Galaxy Legend The Movie.