He enters the Big Croon and Swoon Contest in the "Square and Warmer" story of #2 (September-October 1947). The winner is whoever makes the most girls swoon. He can sing, but only in the bath, so has to perform in a tub. This gag was reused in "The Flintstone Canaries" episode (10/24/1964) of animated television series The Flintstones.
His name is a reference to the song "You're a Square from Delaware" by Fats Waller.