Kathy Griffin was trying to be secretive when she tweeted this photo of herself holding a Warblers uniform, but any true 'Glee' fan already knew that Griffin is scheduled to guest star as a judge in the upcoming Regionals episode.

"Ok Kath-eters, can u guess where I am???...," the red-headed comedian tweeted yesterday, along with a picture of herself masked by a Dalton Academy Warblers uniform.

Griffin gave multiple Twitter updates from her first day on the 'Glee' set, including a video of Matthew Morrison (Will) and Cory Monteith (Finn) helping her elderly mother, Maggie Griffin, out of a van.

In her 'Glee' debut, Griffin will portray a tea party candidate -- a Sarah Palin-esque character -- who will judge the glee clubs, including New Directions, at Regionals.

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