Now, of course there aren't any real three-headed dragons, like Tonok, in the world, but there are dragons. The Komodo dragon is the largest lizard in the world.  They can grow up to ten feet long, and weigh up to 200 pounds.  But even at that size, they can still run as fast as a dog. These dragons can be found on the island of Komodo, Rinca and other islands in Indonesia.