Left to right: beaver, nutria, groundhog, muskrat. An adult nutria is about 1/3 the size of an adult beaver and over 5 times the size of a muskrat. Beavers have broad, dorsally-flattened (top to bottom) tails and black whiskers. Muskrats have virtually hairless, laterally-flattened (side to side) tails and black whiskers. The nutria in this image has a stub-tail, likely caused by frostbite. Neither beavers nor muskrats have a white muzzle or white whiskers.
Look like a groundhog or a woodchuck.. I wonder if it could chuck wood.
And if so, then how much?