Friends

The original idea for the show was going to focus on four characters with Phoebe and Chandler in supporting roles. In the early stages the creators toyed with the idea of Chandler being gay. They changed their mind when they met Matthew Perry. They did, however, insert many jokes about Chandler having gay mannerisms (not knowing about sports, loving show tunes, etc.).

Lisa Kudrow was terrified of the duck that showed up in Season 3.

Because of a bet between Matthew Perry and Bruce Willis on the set of Falsas apariencias (2000) (which Perry won), Willis appeared in his three-episode guest role for free. Willis went on to win an Emmy for his guest role in Friends (1994).