Largest: Blue Whale
These marine mammals can grow up to 100 ft long and weigh up to 200 tons. They maintain this huge size on a diet of small shrimp-like animals called krill which they filter out of the water with plates called baleen instead of teeth.
Although this is still debated, the sailfish is a candidate for the fastest swimmer in the ocean clocking in at 68 mph. Other contenders include the mako shark and the spotted dolphin.
One of the slowest sea creatures is the seahorse. They can reach a maximum speed of only 0.5 mph and are also poor swimmers which is why they are usually found around coral and fans.
Most Deadly: Box Jellyfish
The box jellyfish have venom that is some of the most deadly in the world. A sting from a box jellyfish can be so painful that victims go into shock or suffer heart failure. These invertebrates are found in Australia and have 15 tentacles that can reach up to 10 feet in length.
One of the deepest sea creatures is the viperfish, found at about a mile below the ocean surface. Viperfish lure in their prey with a light-producing organ called a photophore on a long dorsal spine. They then attack with their fang-like teeth so quickly that their first vertebra must act as a shock absorber.
Most Badass: Mantis Shrimp
These colorful stomatopods are aggressive predators that attack prey with either a spearing or smashing mechanism that fires at an acceleration the same as a .22 bullet. They strike so rapidly that cavitation bubbles often form between them and their prey which hit the prey with a second shock wave as strong as 1,500 Newtons of force.
Creepiest: Bobbit Worm
Bobbit worms are the creepiest “Creepy Crawlers” of the ocean floor. Reaching up to 10 ft in length, these worms burrow into the sediment so that only their antennae are exposed, waiting for unsuspecting prey. When these antennae are stimulated, the bobbit worm snaps its teeth together so quickly that prey are often sliced in half. Check out this video of a bobbit worm attacking a lionfish: