July 06, 2018 at 06:07 PM EDT

A star-studded cast of comedy royalty helped celebrate the 20th anniversary of Upright Citizen Brigade theater’s Del Close Improv Marathon, which opened with a Amy Poehler and Tina Fey reunion at Carnegie Hall.

UCB performers like SNL alum Horatio Sanz are sharing with EW memories of their time with the group, like when he would have to beg for tips after shows to buy bins to collect the water that dripped onto performers from the theater’s leaking ceiling, but a lot has changed in 20 years.

Though it wasn’t always glamorous, the theater has always been a reliable go-to for spotting the next big comedic talent. “Rachel Dratch and Tina Fey had a sketch show that I saw so many times I memorized it and like a psycho I would be back by the light booth mouthing all the words,” former Playing House star Jessica St. Clair confessed. “And to this day when Tina Fey enters a room, if I’m there, she feels unsafe but doesn’t know why.”

UCB is also known for its celebrity drop-ins. “We convinced Brooke Shields to come on and play Brooke Shields,” Paul Scheer says. “It was one of the highlights to have Brooke Shields [there] at three in the morning.” “Robin Williams showed up to do an Improv Jam and it was amazing,” Colton Dunn remembers.

In the world of improv the wrong audience suggestions can really kill a show, and as the performers share their favorite DCM memories, they reveal that the most scatological suggestion is not always the best. “Worst suggestion you can get as an improviser is proctologist,” St Clair says. Other contenders: cream corn, dildo, and sperm. “One time,” Lennon Parham shares, ”we asked for a suggestion and a guy screamed out, ‘Be funny!’”

Watch these legendary improvisers share more of their favorite DCM memories in the video above, and then read comedians’ wildest UCB memories here.