Katy Perry looks ready to 'Roar' in her full-length pink leopard print dress This image appears in the gallery:Jingle Bell Ball 2013 Red Carpet: The Stars Arrive For The UK's Biggest Christmas Party! 13. Katy Perry looks ready to 'Roar' in her full-length pink leopard print dress Picture: PA Photos 33 images See the full gallery: Jingle Bell Ball 2013 Red Carpet: The Stars Arrive For The UK's Biggest Christmas Party!