Oh no! Rahu got the Sun!

This story took place during a period when the asuras (demons), led by Bali, were gaining control of the three worlds. The devas (gods) sought guidance from Lord Vishnu. Vishnu proposed that both sides come together to churn the cosmic ocean in order to obtain amrita, the elixir of immortality.

The churning was an elaborate process. Mount Mandara served as a churning rod, with the serpent King Vasuki (Lord Shiva's naga) offering himself as a churning rope. Herbs of every kind were tossed into the ocean. And out of the ocean, many treasures arose, including the Goddess Lakshmi, shankha (Vishnu’s conch), and the apsaras (celestial dancers), one of whom would later become the progenitor of the Khmer race. At the end, the celestial physician Dhanvantari emerged, holding the jug containing the elixir.

The demons seized the jug, and a battle ensued between the two sides. Vishnu, in the form of the enchantress Mohini, his only female avatar, beguiled the demons into handing over the jug to her. She then dispersed the elixir among the gods. One demon, Svarbhanu, who had his eyes fixed on the jug the entire time, disguised himself as a god in order to drink the elixir. Surya (the Sun) and Chandra (the Moon) noticed and informed Vishnu, who proceeded to behead Svarbhanu instantly. However, Svarbhanu had already consumed the elixir, and as a result, his head became immortal and was known as Rahu. But since he was beheaded before the elixir could pass down his throat, his body died.

Rahu is naturally enraged with the Sun and the Moon. He hunts them to take his retribution, and every now and then he catches up to either one. Rahu is merely a head, therefore when he approaches the Sun or the Moon, he tries to swallow them. Rahu occasionally manages to swallow the Sun or the Moon entirely. However, as he is bodiless, the Sun or the Moon ultimately reappears again.