In the epic poem the Mahabharata, Krishna plays a major role that serves as the starting point for a change in Hindu practice. In the poem, he serves as the charioteer for Arjuna, who is about to go into battle against many of his relatives.
As Arjuna sits dejected knowing that to be victorious he must slay his half-brothers, Krishna delivers his celebrated oration, the 'Bhagavad-Gita' (The Song of the Celestial One), on duty and life to the troubled hero Arjuna. This speech persuaded Arjuna that although he was torn by loyalty, it was right to fight against his kinsmen since they were unrighteous.
Krishna expounds a philosophy of right action being the ideal path of salvation, as opposed to relying on ritualistic sacrifices and idol worship as a means of salvation. He states that while yoga and devotion might lead to oneness with God, righteous conduct is better since it helps in both the spiritual and material worlds. The two former methods, Krishna notes, were only focused on the spiritual worlds.
In other works, Krishna is considered to be quite a prankster, who spends much of his time watching over cowherds and seducing milkmaids. It is common to see both aspects of Krishna in Hindu artwork, that of a soldier/philosopher, and that of a child or young man looking after cowherds.
Krishna's Appearance in Statues and Artwork
Unlike many if not all Hindu gods and goddesses, Krishna is usually depicted in statues with only two arms, often playing a flute or with a cow. This has to do with Krishna being an avatar of Lord Vishnu.
Krishna and Radha, His Worldly Consort
Many images and statues depict Krishna with his consort Radha, as they are believed to be ideal lovers. Krishna is playful and kind with her, while Radha is committed and caring of Lord Krishna. Just as Krishna is considered to be an avatar of Vishnu, Radha is considered to be a worldly incarnation of the goddess Lakshmi, who is Vishnu's consort in heaven.
Hare Krishna Movement
Yes, the Hare Krishna people (more formally known as the Krishna Consciousness Movement) is dedicated to Lord Krishna. The followers believe Krishna to be the supreme Godhead, and worship him as such.