From Muppet Wiki

The Flyer's Club is a social dining club located near Sesame Street. In A Celebration of Me, Grover the club gathered to honoring frequent flyer Super Grover.

The club occasionally holds roosts of their members where, as Big Bird explained at Grover's roost, "we all say nice things about Grover - because this is a roost, not a roast."

Big Bird was the roostmaster for Grover's roost, while Bert, Ernie, Elmo, Zoe, Cookie Monster and a penguin sat on the dais. Patrons of the club include Fat Blue, Oscar the Grouch, Grover's Mom, Mumford, Fred the Wonder Horse, and other characters.

Grover worked at the club as a waiter and even waited on people during his roost.

The club is a parody of New York's famous Friar's Club, which holds annual roasts of their members.