Rahu is a Hindu Asura. He is the son of Diti and was present when the gods churned the ocean for the nectar of immortality. Rahu stole some and drank it but had not fully digested it when he was killed by Vishnu. His head became the north lunar node whilst his body became Ketu, the south lunar node. He is believe to be responsible for the solar eclipse.
Rahu in Pali Canon[]
The story goes, that Rahu, whose head has been severed by Vishnu attacked the deities Chandra and Surya, the moon and sun deity respectively. The two are believe to be the one to tell Vishnu about Rahu's action, and thus cause him to seek vengeance on them. This serves as an explanation to the solar eclipse phenomenon. Eventually, Rahu was convinced to release both deities.