Ultraman S01E20 - The Undersea Humanoid Ragon

Yuriko covers the story of an underwater volcano near Iwane Island that may cause the Japanese archipelago to sink. After the volcanic eruption, fisherman find an unexplained gelatin-type object which was accidentally left behind by someone (or something). A series of attacks causes Ishii to conclude that the strange object is an egg that belongs to a prehistoric humanoid, the Ragon.