The people of Liverpool REALLY brought their A-game to the Monster Mash-Up! This image appears in the gallery:#MonsterMashUp 2016: ALL The Photos From Last Halloween's BIGGEST Party 73. The people of Liverpool REALLY brought their A-game to the Monster Mash-Up! The costumes were just INSANE! (Pic: PA) 77 images See the full gallery: #MonsterMashUp 2016: ALL The Photos From Last Halloween's BIGGEST Party