Life in the oceans is much more diverse than life on land; oceans have many more different kinds of organisms. They are full of the biggest, smallest, fastest, weirdest, coolest, spookiest stuff: whales, phytoplankton, jellyfish, sponges, sea dragons, marlins, giant squid, hatchet fish, seaweed, starfish, sea cucumbers, manatees, coelacanths, and stingrays, to name a few.