It's a big ol' leatherback turtle, and a couple of weeks ago it washed up on the Nauset Beach, Cape Cod. The New England Aquarium's Marine Animal Rescue Team came around to attend to the beast (dunno if he's getting sunscreen there, or conditioner, or what). They were able to get him safely back into the water.
Turns out these giant beasts head into the Massachusetts waters about this time of year, to eat jellyfish.