Jason Segel -- The Great Muppet Mix-Up

6/28/2011 12:05 AM PDTby TMZ Staff Jason Segel is not an actual Muppet -- even though he stars with 'em in the new Muppet movie -- and Fozzie Bear refuses to do full frontal nudity!! Still, one dude can't keep 'em straight in his head.Check out TMZ on TV -- click here to see your local listings!