There's a super, secret surprise guest being teased for tonight's "So You Think You Can Dance" finale -- and we've just found out that it's Ellen DeGeneres!
We're told Ellen recorded a number with professional dancer Twitch last night for the finale -- and she was "absolutely unbelievable."
The performance was taped last night because Ellen was unavailable to do it live tonight, when either Robert, Lauren or Kent will be crowned as this season's winner.
