Related Clues:

• Long and slimy
• Long, wet, and snakelike
• Wriggly and slimy
• It's slippery, see — that's what we hear
• Moray-like
• Hard to capture
• Slippery and sinuous
• Slippery and hard to catch
• Difficult to get hold of drug, see?
• Difficult to hold
• Like a slippery catch, hard for the blessed fellow to miss!
• Adjective for 51-Across
• Relating to long fish
• Difficult to catch oriental assassin who's lost tail -- and he's back on the turn
• Hard to get hold of