Neptune's moon is a moon that appears in the episode "Feral Friends."
It is a lime green, glowing moon with three dark green spots that appear to represent a face.
Role in episode
Every 100 years, Neptune's moon appears out of a volcano. Any sea creatures who gaze at the moon will transform into real sea creatures for 2 hours. After that, the moon goes into another volcano and stays there for another 100 years.
Once the moon goes into another volcano, the sea creatures revert to their normal forms, but unfortunately for them, the effects of the moon also caused their clothing to dissolve into nothingness and when they revert, they end up being naked. It is always followed by Neptune's sun.