The Worlds Biggest Asshole Share definition Flag Denis Leary. He actually has a song in which he admits this. "Cause I'm an asshole, the worlds biggest asshole" - Denis Leary The Worlds Biggest Asshole by phuquer May 18, 2011 0 0 Get merch Get the The Worlds Biggest Asshole mug. Buy Now — $32.95 See more merch