The Leatherback Turtle is the largest turtle species in the world. They can grow up to 4.5 to 5.5 feet long and weigh up to 2,200 pounds! Good luck lifting one of those humungous critters!
The reason why Leatherback Turtles are called like that is because they have touch skin that mimics a sort of rubbery leather. The most interesting part to this is that in the millions of years of their existence, their appearance and tough skin have never changed.