Uncle Wally

Uncle Wally was Miss O's uncle, who appeared on Sesame Street from season 2 (first visiting in ) through season 20. A traveling salesman, Uncle Wally was initially an itinerant visitor to Sesame Street before settling down.
An occasional teller of tall tales and dispenser of gags, Uncle Wally was one of the few adults to initially believe Big Bird about Mr. Snuffleupagus, and had claimed to encounter other Snuffleupaguses over the course of his travels.
Before choosing a vocation, Uncle Wally had served in the merchant marines where he learned the song "S.S. Forgetful" (Episode 2130). He introduced Professor D. Rabbit and Garbo — two colorful characters he'd met in his travels — to his friends on Sesame Street, and later brought along his pet seal, Wolfgang, who remained on the street after his departure.
In Magic on Sesame Street, he mentions having a brother named Filbert.