"Undersea creatures" refers to living beings that exist and thrive in the ocean or other bodies of water. These can include fish, whales, dolphins, seahorses, starfish, and various other creatures that live underwater. Full definition
The whimsical children's store Land of Nod makes this activity floor mat with whales, snails, jellyfish, and other undersea creatures. (rookiemoms.com)
Ingenious physiological accommodations have evolved to enable a stunning variety of undersea creatures to be remarkably transparent (scientificamerican.com)
From changing shape, to mesmerizing its prey, to moving with seemingly impossible speed and agility, viewers get to see first hand how one of the smartest undersea creatures earned the title «Kings of Camouflage.» (rottentomatoes.com)