Blacklight Harry Potter tattoo - underneath the footprints it says “I solemnly swear that I am up to no good” in clear UV-reactive ink, meaning it only shows up under a black light. OMG THIS IS AWESOME.
George's mirror of erised. To George, every mirror is the mirror of erised. What he desires is his brother and they look alike so whenever George looks into a mirror, he sees Fred. This is really sad but very well done