That's a 53 lb. Snapping Turtle that was rescued from a drainage pipe near Hockley, Texas earlier this week.
The article that contained this picture said that Alligator Snappers are endangered, but I'm not so sure about that. They are a pretty common sight in the ditches here in Northeast Harris County, and we had one living in the flood control ditch where it goes under our road that is at least this big. He may still be there, but I haven't seen him in a while.