Also pretending to be Tiger Woods and Don Cheadle, the Gang recognizes the actor pretending to be then-Eagles QB Donovan McNabb as “that guy from The Cosby Show who played” Alvin*, who was Sondra’s husband.
*It’s actually Elvin (Tibedeaux; played by Geoffrey Owens), but the characters from Always Sunny say Alvin so this hint should, too. I guess?