Dr. Denise "Jo" Mahoney

Jo Mahoney is one of the new crop of interns at Sacred Heart, thrown in among older students and unimpressed by the hospital's established pecking order. She's blunt, ambitious, and quick with a cutting remark, treating the ladder to becoming a real doctor as something to climb over anyone in her way.

Eliza Coupe plays her with a flat, deadpan aggression that cuts through Scrubs' usual whimsy—she's funny precisely because she refuses to be charmed by the show's sentimentality. Jo works as a jolt of new energy late in the series, a character who treats the sacred rituals of Sacred Heart with open, hilarious contempt.