I could be wrong, but I think it's the infamous "Get off my phone forever" from:
December 7, 2004: Tim And Eric From 'Tom Goes To The Mayor' Stop By For Some Fun. Gene Simmons Tries To Sell Tom Some Stuff. Some Talk Of How American Chocolate Is The Best, And The Absolute Final Captain Jack Appearance.
I myself would like to know the origin of the big "The" at the beginning of the theme.