Periodically, as recorded in Hindu myth, forces of evil threaten to endanger the universe. At such times Vishnu as the Preserver assumes a "descent form" (avatar) in which to vanquish them. Such forces are usually personified as demons against whom he wages titanic battles or outwits by cunning. There have been nine past occasions when Vishnu's intervention has been necessary to preserve the universe. In one of them he assumed mortal shape as Krishna, son of cowherds living in northern India. Among Krishna's many myths, one recounts how as a mischievous toddler he crawled away from his mother and stole a ball of butter. These three small images in stone, copper, and bronze refer to this event, depicting Bala (Baby) Krishna crawling along with the stolen butter in one uplifted hand.