The Bakunawa, also called the Philippine moon-eating dragon, the Philippine moon dragon, moon dragon, or the moon-eating dragon, is a serpent, that looks like a 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 rituals of the babaylan priestess. It is usually depicted with a characteristic looped tail and a single horn on the nose. It was believed to inhabit either the sky or the underworld.

Due to increasing trade contacts with South Asia and the Indianization of Southeast Asia, the Bakunawa later became syncretized with the Nāga, Rahu, and Ketu of Hindu-Buddhist mythology.

Bakunawa is believed to be originally a compound word meaning "bent snake", from Proto-Western-Malayo-Polynesian *ba(ŋ)kuq ("bent", "curved") and *sawa ("large snake", "python"). Spelling variants include Vakonawa, Baconaua, or Bakonaua.

"No. 42. When the moon is eclipsed, the Indians of various districts generally go out into the street or into the open fields, with bells, panastanes, etc. They strike them with great force and violence in order that they might thereby protect the moon which they say is being eaten or swallowed by the dragon, tiger, or crocodile. And the worst thing is that if they wish to say "the eclipse of the moon" it is very common in the Philippines to use this locution, saying "the dragon, tiger, or crocodile is swallowing the moon." The Tagalogs also make use of it and say, Linamon [ni] laho [ang] buwan [trans.: "Laho swallowed the moon"]."

Fr. Tomas Ortiz, Practica del Ministerio (1731) via Zuniga's Estadismo (1893)

The Bakunawa is also sometimes known as Naga, from syncretization with the Hindu-Buddhist serpent deity, Nāga. It was also syncretized with the Hindu-Buddhist navagraha pair, Rahu and Ketu, deities who were responsible for eclipses of the sun and moon, respectively.

Versions of the Bakunawa also existed in other myths in the Philippines, sharing the common theme of being the cause of eclipses. The most similar to the Bakunawa is the Tagalog Laho (derived from Rahu; also known as Nono or Buaya), a serpent-like dragon that causes moon eclipses. In Kapampangan mythology, Láwû is depicted as a bird-like dragon or serpent that causes both solar and lunar eclipses, however, its features are closer to the demon Rahu. Both the words laho and láwû mean "eclipse" (also in modern parlance "to disappear" or "to vanish") in the Tagalog and Kapampangan language.

Other mythical creatures related to the Bakunawa include the Hiligaynon Bawa, Bauta, or Olimaw; the Mandaya and Manobo Tambanakua; the Bagobo Minokawa; and the Maranao Arimaonga. However, these do not always appear serpent-like. The Maranao Arimaonga for example, is depicted as a lion-like dragon; while the Hiligaynon Olimaw is a winged serpent; the Bagobo Minokawa is a dragon-like giant bird; and the Mandaya Tambanokano and Manobo Tambanakua is a giant crab (sometimes also a giant tarantula or scorpion).