Philadelphia's mayor on Tuesday vowed to find the "coward" who left a pig's head at the door of a Philadelphia mosque. The head was found outside the Al-Aqsa Islamic Society early Monday morning. "We all know of the terrible, thoughtless, ignorant act that someone perpetrated in this city yesterday," said Mayor Michael Nutter. "We will, of course, at some point in time find the coward." Pork and pork byproducts are haram, or forbidden, in Islam.