Related Clues:

• River denizens
• First try for Ulster playing slow types from overseas coming out of their shells
• Reptiles with bony shell and flipper-like limbs
• Slow-motion operators?
• Animals symbolizing the universe in Chinese culture
• Pets kept in terrariums
• They're shelled with a twist of mussel -- truthfully, that covers it
• Reptiles swagger around, encircling the Parisian
• Trunks almost all removed — smashing result for swimmers
• Maybe Leonardo and Donatello produced result after time