16 celebrities you forgot were on ‘ER’

START THE DAY HERE Early voting turnout strong in North Carolina. What Hamas leader's death may mean for war in Gaza. Investigation into Liam Payne's fatal fall continues. Entertainment 16 celebrities you forgot were on ‘ER’ The "Breaking Bad" actor helps Dr. Greene diffuse a bomb in Season 5's "They Treat Horses, Don't They?" Chadwick Boseman — The future "Black Panther" shares the screen with Carl Weathers in a Season 15 episode, playing a young boxer who comes into the ER after taking a beating in the ring. Before he was baddie Negan on "The Walking Dead," Morgan played a firefighter who needs the help of ER docs in the field after he gets trapped underneath a turned over train in the show's 150th episode. The future voice of Olaf from "Frozen" guest stars in Season 11's "Here and There" as a man serving with Dr. Gallant in Iraq. The Oscar-winning actress plays a patient named Maria Jones, a pregnant woman who has severe abdominal pain, in Season 5's "Hazed and Confused." Park plays a man with developmental delays whose teenage sister has a baby in the ER in a Season 11 episode. The Oscar nominee appears in Season 10's "Forgive and Forget" as a woman who takes care of her sick father. The future "American Horror Story" star played one of two Amish teens who are involved in a car accident in Season 10. Offerman shows up in a Season 4 documentary-style episode ("Ambush") and plays a man whose friend comes in under respiratory distress.