"The Roommate Transmogrification" is the fourth season finale of the television series The Big Bang Theory that first aired on CBS on May 19, 2011. It is the twenty-fourth episode of the fourth season of the series and the eighty-seventh episode overall. Aarti Mann continues her recurring role of Priya Koothrappali while Brian George and Alice Amter reprise their roles of Dr. and Mrs. Koothrappali in this episode.