Updated:Guillermo del Toro is putting his spin on The Simpsons. The "Pacific Rim" filmmaker is throwing in a horror history lesson, of sorts, for the animated Fox comedy's opening credits, for its upcoming "Treehouse of Horror XXIV" Halloween special. Instead of the usual opening, del Toro ? a former special effects makeup artist in Mexico ? created a sequence featuring monsters and classic horror characters from films of the past several decades.