Indra, in Vedic myth of Hinduism, god of the atmosphere, storms, rain, and battle. Indra is the most celebrated Vedic god, with more than 250 hymns addressed to him. Ancient legends depict him as the most powerful foe of various demonic powers preventing the rain and the dew from nourishing the earth. In later Hinduism, Indra is subordinate to the gods Brahma, Shiva, and Vishnu. He is depicted as penitent, somewhat dull-witted, and often perplexed by more popular gods and heroes. In Hindu art Indra is frequently represented as having four arms: one hand holds a thunderbolt, the second wields a spear, the third holds a quiver of arrows, and the fourth carries a net of illusions and a hook for entrapping foes.
(From Microsoft Encarta Concise Encyclopedia)
In the Rig Veda, which is a collection of antique Hindu hymns, Indra is described as the king of the gods. He has authority over the sky and the power to make rain using his weapon the thunderbolt. Indra is depicted as a man with four long arms riding a white elephant. Indra is the god of battle. Before each battle, he drinks a vast quantity of soma which makes his belly enormous. The soma is a divine juice. It is said that this juice empowers him to accomplish his heroic missions. His strength defeated the serpent Vritra who had swallowed all the waters of the world bringing a tremendous drought. Indra split the belly of the serpent with his thunderbolt, releasing the waters and generating life. By killing the serpent, Indra separated land from ocean, and caused the sun to rise.