Related Clues:

• Risky venture
• Hardly a favorite
• One against the odds
• Unlikely winner
• Big underdog
• Unlikely success
• Long shot
• Black Beauty, e.g.?
• It might pay big at the track
• Wild guess or venture - using rifle?
• Successful competitor of whom little was known, like colourless equine
• Little-known competitor like shadowy equine
• A wild venture or guess - even for marksman?
• You don't know the form this nightmare may take
• You can't tell what form this nightmare will take