What was the most unexpected crossover on Friends?

One of the most beloved sitcoms of all time, Friends, ran for ten seasons from 1994 to 2004, and over the course of its run, there were a number of memorable guest stars and cameos. However, the most unexpected crossover on the show was the appearance of Danny DeVito, who played the character of Roy, a stripper at Phoebe's bachelorette party.

DeVito's appearance on Friends was unexpected for a number of reasons. Firstly, he was already a well-known actor, having starred in hit movies like Twins and Batman Returns, so it was surprising to see him on a TV show, especially one that was already so popular. Secondly, his character of Roy was very different from the roles he was known for playing, such as the lovable Louie De Palma on Taxi.

Despite the unexpected nature of DeVito's appearance, his character of Roy was a hit with fans and has become one of the most memorable guest appearances in the show's history.