Judd Hirsch as Dr. Alfred Hofstadter
Judd Hirsch played Leonard's father, Dr. Alfred Hofstadter, on The Big Bang Theory. An anthropologist who was miserably married to Beverly, Alfred eventually struck up a relationship with Mary Cooper, Sheldon's mother. Toward the end of the series, he and Beverly agreed to be civil for Leonard's sake.
Ian Scott Rudolph as Captain Sweatpants
Captain Sweatpants was played by Ian Scott Rudolph. A middle-aged bald man whose signature outfit was gray sweatpants and a Captain America t-shirt, Captain Sweatpants frequented the guys' favorite comic book store. He is friends with Wil Wheaton and another comic book store misfit, Lonely Larry (Owen Thayer).