Tommy is a parody of Wally Cleaver, the older brother character from Leave It to Beaver, a classic American sitcom about a suburban family. When Cosmo and Wanda poof up Tommy, the name "Wally Beaver" appears as the poof cloud.
In order to compensate for having an older child, Timmy's wish for Tommy make Mrs. Turner become much older.
Timmy had to wish a fake country when his friends asked him where Tommy came from. The country is called "Tibecuador", and later episodes sometimes reference this country as existing.
Timmy also got an older brother named Tommy in the storybook Too Many Turners. Unlike the character's appearance in the series, the book's version of Tommy depicted him as resembling a taller Timmy wearing a blue shirt, blue pants, and blue tennis shoes.