It's the same voice he uses for the henpecked mailman Mr. Beasley on the radio program, "The Burns and Allen Show." His catchphrase (which he also uses for the Easter bunny) is "And remember: keep smiling!"
That's a reference to the juvenile delinquents from Dead End (1937) (1937), who were spun off into a popular series of dramas and comedies. The kids are known as the Dead End Kids, the East Side Kids and the Bowery Boys.