The term PLAYFUL SEA CREATURE can be described by two crossword solutions: PORPOISE (8 letters) and OTTER (5 letters). Porpoises are small toothed whales that are found in coastal waters around the world. They are known for their playful behavior, such as leaping out of the water and playing with objects. Otters are semi-aquatic mammals that live in rivers, lakes, and oceans. They are also known for their playful behavior, such as sliding down muddy banks and playing with rocks and sticks. Both porpoises and otters are popular animals in zoos and aquariums due to their playful nature.