Possible Clues:

• Eellike fish
• Eel look-alikes
• Eel-like fish
• Fishlike jawless vertebrates (of which Henry I is said to have eaten a surfeit and died)
• We hear innocent creature speak well of parasitic suckers
• More than one bloodsucker strikes to secure victim
• Eel-like creatures
• Fish as start of meal adorned with chopped parsley
• Fishes will make attacks swallowing creature as food
• Marine suckers