While Gary is said to be the older brother of Walter, the two brothers are very close in age. The two are shown in the same first grade class, and also participate in the same JPA Troop and play on the same baseball team. When their heights are recorded, both Gary and Walter are marked as being the same age at the time of the measurings (the brothers are shown in the film being measured together at ages 6 and 13). In the film's opening narration, Walter says "That's my brother Gary. He's the best friend you could ever have. Yeah, I know what you're thinking, we could be twins."
The three young actors who play the character "Gary" at different ages in The Muppets are shown posing on the set during filming. Pictured from left are: Justin Marco, Connor Gallagher and Gunnar Smith.