Koschei The Deathless

Koschei The Deathless is an evil wizard from Russian fairytale. He kept his soul not in his body, but hidden in a duck's egg; he could thus not be killed in the normal way, but could be killed by destroying the egg.

Koschei, or things named after him, make appearances in:

• 'The Firebird', a ballet by Igor Stravinsky
• James Branch Cabell's Poictesme books (where he's also the creator of the universe)
• 'A Colder War', where the name is a codename for Great Cthulhu
• The Sandman, somewhere
• 'Monday Begins On Saturday', by The Strugatskii Brothers?, where Koschei is the name given to an immortal monster held in the Academy of Sciences Institute of Thamaturgy and Advanced Magic
• Doctor Who: The Dark Path by David A. McIntee, where Koschei is the given name of the Time Lord who will eventually turn out to be the Master.