1. Megalodon
We always hear about the Megalodon during Shark Week on Discovery Channel, but it is for a good reason. The Megaladon species has fascinated humans for years. Just think, a giant shark? Sharks now are horrifying but if the Megaladon lived today it likely would trump all other horrifying sea monsters in the world.
They measured in often more than 50 feet in length! The jaws of the shark were so large that grown adults could walk through the opening. The species was known to hunt whales, as they were likely the only big meal they could get. It is widely believed that the extinction of the Megalodon is what allowed whales to grow so large. Without another species cutting them down, they were only able to grow. The last known Meg died 3.6 million years ago, which is eery as early humanity began at this time.