Slumber Party Clarence struggles to make a connection at an all-girls slumber party, leaving Sumo and Jeff at odds without Clarence as their "friendship buffer." Details Casts Title Slumber Party Genres Animation Comedy Release Date 2014-08-07 Episode Runtime 00 Hours 11 Minutes Season Number 1 Episode Number 16 Production Companies Cartoon Network Studios Spencer Rothbell Clarence / Camden / Mavi? Skyler Page Clarence / Mr. Reese / N? Tom Kenny Sumo (voice) Sean Giambrone Jeff (voice) Katie Crown Mary / Ms. Baker / Ms. S? Eric Edelstein Chad (voice) Roger Craig Smith Belson / Percy (voice)