A line by Foghorn Leghorn in the old Warner Bros. toons, but, like Leghorn, it comes from a character on Fred Allen's radio show - the loud, proud, Southern man Senator Claghorn ("Ah ain't settin' foot in YANKEE Stadium less'n that DIXIE Walker's playin'", etc). "That's a joke, son" often punctuated a punch line that fizzled (deliberately?) or left Mr. Allen dumbfounded. Kenny Delmar did the voice; he was once in Orson Welles' Mercury Theatre troupe, of War of the Worlds fame.