In 2003, Australian researchers attached a tracking tag to a great white shark to study its movements in the open ocean.
A few weeks later, a bizarre event occurred: the tracking data showed the shark was suddenly sucked down to the very bottom of the ocean floor, while the device's temperature sensor instantly shot up from 7°C to 33°C, the exact internal temperature of a living body.
The data led researchers to a terrifying conclusion: the apex predator had been swallowed by an even larger species. To this day, scientists still don't know what kind of creature could possess the power to consume a great white shark, heavily suggesting that gigantic, unidentified monsters are lurking in the deep ocean.