The comedian and My Life On The D-List star will appear in the eighth episode of the new season as Kim's (Kate Levering) sister, reports The AP.
The character will reportedly have a run-in with Margaret Cho's character Teri, a plotline which lead Griffin to describe the appearance as "the role [she] was born to play".
Wanda Sykes was recently announced to guest star in episode five which deals with high school student Constance McMillen, banned from her prom because she planned to take her girlfriend. Tony Goldwyn will also join the show's sixth episode.
Other guest stars who have signed up for the next season of the legal drama include LeAnn Rimes, who will play a woman separating from her husband, talk show host and former Dancing With The Stars contestant Wendy Williams and singer Paula Abdul.
Drop Dead Diva returns this summer on Lifetime.
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