There's no Ass Ponys theme song. I like the Ass Ponys a whole lot (haven't heard Wussy, though), but I can't think of any of the three theme songs whose singers sound like Mr. Cleaver. If I had to guess, I'd say you're thinking of Shock the Claw's theme, which features (I think) John Junk. There's also one with 2007 Caller of the Year Paycheck and a third that is based on the song Jak by Volcano Suns.