Jon Hamm to guest star in 'SpongeBob SquarePants' as Don Grouper By (0) Actor Jon Hamm, winner of Outstanding Lead Actor in a Drama Series for 'Mad Men,' holds his Emmy at the 67th Primetime Emmy Awards at the Microsoft Theater in Los Angeles on Sept. 20, 2015. Hamm will guest star as a 'Mad Men' inspired character in Bikini Bottom as "Don Grouper" on 'SpongeBob SquarePants.' Photo by Jim Ruymen/UPI | License Photo Actor Jon Hamm attends the annual Hollywood Foreign Press Association (HFPA) Grants Banquet at the Beverly Wilshire Hotel in Beverly Hills, Calif. File Photo by Jim Ruymen/UPI | License Photo