iPhone 6 / grey / supream sticker

I just lost an iphone 6 in Dublin. It's grey in colour with a clear plastic case covering the back and a plastic screen protector shielding the front. There is also a sticker of a person with bushy white hair, red skin, pink lips and yellow eyes placed on the back of the phone. This sticker reads "supream". I will reward whoever returns the phone to me in working condition with €100.