The Alkonost is the bird of paradise in Slavic mythology.
Etymology
The name Alkonost came from the name of Greek demi-goddess Alcyone transformed by gods into a kingfisher.
Description
It has the body of a bird with the face of a woman. Her voice is so sweet that anybody hearing it can forget everything. The Alkonost reproduces by laying eggs on the sea-shore then putting them into the water. The sea is then calm for six or seven days at which point the eggs hatch, bringing a storm. Unlike Sirin, another similar creature, she is not evil.
For the Russian Orthodox Church, Alkonost personifies God's will. She lives in paradise but goes into our world to deliver a message.