Possible Clues:

• Water animals with webbed feet and flat tails
• To rest in the water
• Fish-eaters arranged to rest
• Frolicking fauna
• Playful carnivores
• Frisky critters
• It's for the rest to be in and out of water
• Fish-eating water animals, put to rest
• Swine, it's said, abandoning river to web-footed creatures
• Abalone eaters