The Bakunawa is a serpent-like dragon in Philippine mythology. It is believed to be the cause of eclipses, earthquakes, rains, and wind. The movements of the Bakunawa served as a geomantic calendar system for ancient Filipinos and were part of the shamanistic rituals of the babaylan. It is usually depicted with a characteristic looped tail and a single horn on the nose. It was generally believed to be a sea serpent, but are also variously believed to inhabit either the sky or the underworld.