Tom Cruise's cousin William Mapother first creeped us out as evil doctor Ethan on "Lost." And he kept the creep factor going when he popped up last season as Roger's insurance pal Randall Walsh, who proposed selling property insurance with an image of a Molotov cocktail and a coupon. Hollywood casting directors, if you need a creepy weirdo, look no further.
The halls of Sterling Cooper & Partners have been filled with a lot of familiar faces lately. Here are more than 20 "Mad Men" guest stars we recognize from previous roles in TV and movies. — Dave Nemetz, Yahoo! TV