The bouncer works at the Secret Holders Club, an imaginary place which D.W. visits in two dreams in “The Secret About Secrets”. He lets D.W. into the club after she learned about James splitting his pants in preschool. When the bouncer realizes she told someone the secret, he wants to throw her out of the club.
The bouncer looks like Rattles with a different color and different clothes.
A lookalike of the bouncer appears in “The Making of Arthur” as Matt Damon’s cameraman.