Sully is a construction worker, and a friend and colleague to Biff, who first appeared in Season 5. Although Sully never speaks onSesame Street, it is suggested that he is indeed capable of speech. In the song "Think of Your Fingers," Biff recalls Sully giving him advice on how to remember the number 5. Also, in Big Bird Gets Lost, while drilling loudly Biff tells Big Bird what Sully says.
In addition to working in construction, Sully is good at playing the piano. However, Biff is sometimes oblivious to this.
Two construction-worker Anything Muppets who looked similar to Biff and Sully made background appearances in the sketch "Outrageous Makeover: Home Edition" sketch. (First: Episode 4132)Also, a stagehand that looked like Sully appeared in the "Survivor: Musical Chairs" sketch. (First: Episode 4134)