It is the colossal squid, Mesonychoteuthis hamiltoni.
Dwelling in the deep waters around Antarctica, this behemoth is truly amazing. It's eyes alone are over a foot across. Reaching over forty feet in length, it still isn't as long as the giant squid. However, it's body is longer and much thicker, giving it a more massive profile.
Also, it has a wicked adaptation the giant squid lacks. Whereas the giant squid only has suckers on it's tentacles, the colossal squid's thick arms are equipped with savage hooks to better snare it's prey.
Pretty amazing, isn't it? I think the coolest thing about this real life sea monster is how many of them there are. Though almost never seen by humans, they are numerous enough to make up 77 percent of the Antarctic sperm whale's diet.
It definitely makes you wonder. What other giant killers lurk out in those unexplored depths?