Behemouth

That whale shark's gaping mouth is almost five feet wide and contains up to 350 rows of teeth. Though the sea creatures are docile, the diver is lucky he wasn't sucked in along with the plankton and tuna that dominate the whale shark feeding frenzy off the coast of Cancun, Mexico.

Photograph By Mauricio Handler
National Geographic Society/Corbis

Whale Shark (Rhincodon Typus) 46ft.

Great White Shark (Charcharodon Charcharias) 23ft.