There are so many extraordinary creatures in the ocean. Some leave us in awe with their incredible colors, others with how they camouflage themselves, and many with how they exist in an ecosystem that differs so drastically from the one we are used to. But what has captivated people for centuries is how massive some of these ocean-dwellers are. Read on to learn about 10 of the largest ocean creatures swimming around out there as we speak.

Land or sea, past or present, the blue whale is the largest animal who has ever existed. The blue whale even towers over the biggest known dinosaurs! They weigh up to 441,000 pounds and stretch half the length of a football field. Their heart is the size of a car and so powerful that it can be detected a full two miles away.

While the blue whale holds the title for overall largest ocean animal, the award for the longest ocean animal goes to the lion’s mane jellyfish. With tentacles that reach an incredible 120 feet, they are at risk for getting tangled in marine debris or their tentacled friends. It’s not as easy for them to contract such massive appendages, but a warning to those with a taste for jellyfish arms – they are filled with poison!

In the category of largest toothed predator, sperm whale comes out on top. While they are as long as an eight story building, they are not actually known for their size. It is their clicking call that garners the attention. They use these clicks, also known as echolocation, to find prey and communicate with each other. Many other animals, such as bats and other types of whales, also use echolocation, but none as loud as the sperm whale. Their clicking call can be up to 230 decibels underwater, and 170 decibels on land. That’s the same as someone shooting off a rifle right next to your ear!

Sharks are often thought of as being in a category all their own, but the whale shark likes to dip their fins in all the buckets. Since sharks are scientifically fish, the whale shark is the biggest fish that swims the ocean. However, this beautiful giant acts more like a whale than a shark. Their mouth can open up to five feet wide and is filled with hundreds of tiny teeth, but they enjoy a diet of plankton and the occasional small fish that finds their way into the whale shark’s giant mouth. They pose virtually no threat to humans or other large animals, and have even been known to tag along with adventurous divers for a swim.

Here we have another gentle giant that roams the ocean blue. It is the second largest fish with the biggest one ever recorded measuring over 40 feet. That’s the length of a school bus! Unlike other sleek sharks, the basking shark has an enormous snout and build that adds to their weight. They weigh in at about 8,500 pounds on average, which is impressive considering they mostly eat plankton, fish eggs and larvae!

Our first cephalopod makes the list! It should come as no surprise that the longest cephalopod is the giant squid (since the word is right there in their name). Other than knowing they are massive and can catch prey that is over 30 feet away thanks to their feeding tentacles, these creatures are still shrouded in mystery. They live deep in the ocean and haven’t been able to be studied much by scientists. But they have been the inspiration for legends and folklore, including the Kraken.

This cephalopod might not outrank the giant squid in length, but with a radial spread of 32 feet, they can cover an impressive amount of ground. Imagine a 32 foot long octopus spreading each of their eight tentacles. They could easily cover a modest-sized home and still not be stretched to capacity! Even with the ability to change colors when they feel threatened, it wouldn’t be hard to spot the giant Pacific octopus.

The oarfish has picked up many nicknames, including “the ribbonfish” thanks to their length, lack of scales and unique shape. However, they have also been referred to as sea serpents or dragons throughout the centuries. They live in the deep dark water columns of the open ocean and don’t make their way to the surface very often. Most of what scientists have discovered about the oarfish comes from the few that have washed up on the shore.

Let us introduce you to the Japanese spider crab. It isn’t just the largest crab. Or the largest crustacean. It is the largest of all living arthropods on land and water! This includes spiders, insects and all sorts of other exoskeleton-having creatures. While young Japanese spider crabs are known for decorating their shells in an attempt to camouflage, their elders rely on their strong claws and large size to defend themselves. Considering their legs continue to grow for their entire lives, it becomes easier to fight than it does to hide themselves!

Compared to the 100+ feet long ocean creatures that we started this list with, 11 feet might not sound that out of the ordinary. But the ocean sunfish is anything but ordinary! They are also known as a mola mola, and sometimes just “a swimming head” because they don’t even have a tail. Even though they weigh over 5,000 pounds, they can swim at a leisurely pace thanks to their mighty side fins. They might not win any ocean races, but they are one of the few fishes that can swim on their side making their movements as beautiful as they are unique.

While all the creatures on this list are amazing, what strikes even more awe into us is the fact that so much of the ocean is still unexplored. Maybe there is an animal even bigger than the blue whale, like a squid that makes our 40-foot long friend look like a toddler or a crab that could snap a sequoia like a twig. Who knows what other creatures are waiting in the depths of the ocean to tell us their stories!