Imagine swimming in the ocean and coming face-to-face with creatures that seem like they belong in a sci-fi movie. Take the megalodon, for instance, a massive prehistoric shark that could easily swallow a small boat—thankfully, it's extinct! Then there's the colossal squid, with eyes the size of dinner plates and tentacles that can stretch up to 46 feet long. Sailors have spun tales of the Kraken, a legendary sea monster that could supposedly drag entire ships underwater. Let's see which of them are real, and which - not so much.

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