Possible Clues:

• Many-headed snake slain by Hercules
• Hard nuts cracked by unknown group of stars
• Hardy (anag.)
• Sea serpent in the night sky
• In classical mythology, Hercules killed this nine-headed monster
• Minute freshwater organism with a tubular body and a ring of tentacles around the mouth
• Mythological monster with multiple heads
• Many-headed snake
• Mythical monster
• Monster in bibliography -- Dracula?