Comedian Kathy Griffin and veteran actress Loretta Devine are set to appear on an upcoming episode of Fox's "Glee."

The duo will play judges at the Regionals competition that will pit Will Schuester (Matthew Morrison) and the New Directions glee club against Aural Intensity -- coached by their nemesis, Sue Sylvester (Emmy winner Jane Lynch) -- and the Dalton Academy Warblers featuring former classmate Kurt Hummel (Chris Colfer) and Blaine Anderson (Darren Criss, this season's undisputed fan favorite).

Griffin -- best known for her "My Life on the D List" series -- will play Tammy Jean, a home-schooling former Tea Party candidate, though recent reports previously suggested that she would be doing a riff on Sarah Palin.

Meanwhile, Devine is taking a break from her "Grey's Anatomy" role to play Sister Mary Constance, a former stripper turned nun.

In last season's finale, singer Josh Groban and "Grease" star Olivia Newton-John appeared as judges for the Regionals competition.

In other "Glee" news, Mike O'Malley has confirmed that he will appear in at least six episodes of the show's third season, despite the fact that the Emmy-nominated actor will take the lead role in a new Fox pilot called "Family Album."