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.