Ultraman S01E23 - Fury of the South Sea

Large footprint sightings in the Tateshina Highlands trigger stories and prompt news reporters to come to the area. Yuriko, however, is not given an assignment. Yuriko learns from an old friend, Ayako, that a rare, Amazonian butterfly called Morpho Menelaus can be found in the area. Ayako's fiancé, Koji, became poisoned by a giant butterfly and later turned into a giant monster.