An All-Star Toast to the Improv

To celebrate the birthday of the renowned Improv comedy club, six famous comedians take the stage to perform their routines. To keep things lively, while each entertainer delivers his set, the other five sit at the back of the stage and heckle the performer. This video is especially notable for Martin Mull delivering a sharp zinger aimed at Robin Williams, silencing the otherwise motor-mouthed comic for at least five seconds.