The noun carrion refers to the dead and rotting flesh of an animal. Ever seen a dead opossum or cat in the road? You can call that road kill carrion.
The word carrion comes from a Latin word caro, which means "meat," but carrion is usually considered unfit for human consumption. Birds of prey and other opportunistic animals will often have carrion as part of their diet, however. Sometimes the word carrion is used a little more metaphorically: "The soldiers were unable to retrieve the bodies of their fallen brothers, so they were left on the field of battle like so much carrion."