Cetus, the Whale or Sea Monster, is an ancient constellation between Pisces and Taurus. A rough pentagon of five stars marks the head of the monster. The principal star in the Whale's head is Menkar, a red giant. The other stars are Kaffalijidhma, Xi2 Ceti, Mu Ceti, and Lambda Ceti. To the east, Cetus also contains the star Mira, the most famous of all variable stars.