Slow-moving killer

The Greenland shark is one of the slowest-moving fish ever recorded and has been found with reindeer, polar bears, and fast-moving seals in its stomach. It's thought that Greenland sharks prey upon sleeping seals, which snooze in the water to avoid polar bears.

Megamouth!

One of the rarest sharks is the megamouth shark (Megachasma pelagios, meaning "giant mouth of the deep"). Fewer than 100 specimens of the beast have ever been seen. It was first discovered in in 1976 when struck by and tangled in the anchor of a Navy ship off Hawaii. The animal can grow up to 15 feet (4.6 meters) long and is a filter feeder, syphoning plankton from the water.