Sirin is a mythological creature of Russian legends, with the head and chest of a beautiful woman and the body of a bird (usually an owl). According to myth, the Sirins lived "in Indian lands" near Eden or around the EuphratesRiver.
These half-women half-birds are directly based on the Greek myths and later folklore about sirens. They were usually portrayed wearing a crown or with a nimbus. Sirins sang beautiful songs to the saints, foretelling future joys. For mortals, however, the birds were dangerous. Men who heard them would forget everything on earth, follow them, and ultimately die. People would attempt to save themselves from Sirins by shooting cannons, ringing bells and making other loud noises to scare the bird off. Later (17-18th century), the image of Sirins changed and they started to symbolize world harmony (as they live near paradise). People in those times believed only really happy people could hear a Sirin, while only very few could see one because she is as fast and difficult to catch as human happiness. She symbolizes eternal joy and heavenly happiness.
The legend of Sirin might have been introduced to Kievan Rus by Persian merchants in the 8th-9th century. In the cities of Chersonesos and Kiev they are often found on pottery, golden pendants, even on the borders of Gospelbooks of tenth-twelfth centuries. Pomors often depicted Sirins on the illustrations in the Book of Genesis as birds sitting in paradise trees.
Sometimes Sirins are seen as a metaphor for God's word going into the soul of a man. Sometimes they are seen as a metaphor of heretics tempting the weak. Sometimes Sirins were considered equivalent to the Polish Wila. In Russian folklore, Sirin was mixed with the revered religious writer Saint Ephrem the Syrian. Thus, peasant lyrists such as Nikolay Klyuev often used Sirins as a synonym for poet.