In astrology Rahu is considered as dragon's head and is known as the north node of Moon, the point where the Moon's orbit crosses the ecliptic.

Rahu is a shadowy planet, fisher-man caste, a female, a Mlechchha, of wicked disposition, moves in apasavya direction, is courageous and daring, has a serpent body, troublesome and cunning. A malefic, resides in mountains and forests, causes pox, worms, suicide.

There is a story behind birth of Rahu & Ketu, which relates to the great churning of the ocean by the Devas and the Asuras to take out Amrita. Lord Vishnu with the intention of preserving good made it a point that the Amrita should not go to the Asuras. To ensure this he took the form of Mohini. Mohini so maneuvered the sitting arrangement that she got to the Devtas first. The Asura to understand this trick was Swarbhanu. He took the form of Devas and positioned himself in between Sun and Moon. When his term came he also received Amrita from the disguised Lord Vishnu. Before Swarbhanu could drink the Amrita Sun and Moon identified it. Lord Vishnu severed off his head with his Sudarshan Chakra. However, some drops of Amrita had gone down hence both the head and body became immortal. The head represents Rahu and Tail is Ketu.

Umbrella, kingdom, gathering, fallacious argument, hurting by speech, downcast, wicked woman, decorated vehicle, an irreligious man, gambling, strong at twilight, going abroad, impurity, bone, enlargement of spleen, falsehood, downward look, perplexity, facing the Southern quarter, shelter of outcaste or low people, painful swelling, a big forest, wandering in rugged places, mountain, pain, staying outside, tending towards South-West, wind, phlegm, sorrow, serpent, night breeze, sharp, long, reptile, reading of dreams, trave