Watch 'Big Bang Theory' star Kunal Nayyar sing Boyz II Men 'Big Bang Theory' star Kunal Nayyar is writing a memoir 'The Big Bang Theory' cast on last season's finale and their top moments of all ...

Now, one of the original cast members has officially weighed in. Kunal Nayyar, who played Rajesh "Raj" Koothrappali, just reunited with former Big Bang Theory co-star Melissa Rauch on Night Court.