Liane Cartman called up Dr.Roberts after some concern that Cartman had lost 112 baby teeth. Cartman used the teeth in order to receive Tooth Fairy money to save for a Sega Dreamcast. Dr. Roberts was unable to provide advice to Liane due to the American Dental Association convention.
At the convention he spoke to the audience about reports of missing teeth. He provided a farfetched reason, that everyone in the audience, except Tom Foley took as truth, as to who the culprit of the missing teeth was. He described a giant half-chicken/half-squirrel with a "mild understanding of algebra". He also stated that the creature would steal either the money or the teeth from children to build a nest for its dangerous offspring.
Dr. Roberts wears a light-teal dentist lab coat over a red vest with yellow buttons, which is also over white button shirt with a thin black tie. He is bald, wrinkles on his forehead and chin, and black eyebrows. Roberts' coat has a tag that says ADA, which stands for the American Dental Association. Roberts also has a dental tool in his coat pocket.