It was fourth year, and Luna had a whim to give someone a tattoo. It was a silly whim, one that appeared in her head late at night, but Luna felt a strong need to follow up on it. She immediately started to rummage through her trunk in a rather unsystematic way, pulling out things just to put them back in and find them again after a while instead of putting them to the side as to not accidentally grab them more than once.
After a good while, she found what she was looking for: a jar of magic color-changing ink that was often used for the covers of the Quibbler that her father gave her and a sewing needle. She smiled to herself as she skipped out of the Ravenclaw girls' dormitory and over to the Gryffindor girls' dormitory. She knocked on the door, waiting for her friend to open the door. A couple minutes went by before Ginny appeared, messy-haired and half-asleep.
Luna told her the fantastic whim she had, and that she must give her a tattoo. Ginny yawned and reluctantly agreed, so long as she could go back to bed as soon as it was finished. Luna thanked her and enthusiastically took her hand and lead her back into the dormitory.
They sat on the floor, Luna dipping the needle in the ink and Ginny rubbing the sleep out of her eyes. Luna got up from her spot to grab a wet rag from the bathroom. She wiped off the inside of Ginny's forearm, telling her that's where it should be. Ginny nodded, succumbing to whatever plan Luna had in her head. The tattooing began after that, and it didn't take very long. Once it was finished, it was a tiny crescent moon, like the one in the sky that evening.
"It'll tell you the weather and it'll glow when the weather is perfect for quidditch." Luna told her. Ginny thanked her with a hug, then trudged off to bed. Luna smiled again, packed up her ink and cleaned off the needle, and headed back the her own dormitory to get some sleep herself.
~o0o~
Found a prompt on tumblr for Luna as a tattoo artist and I had to write it. There'll be more chapters that coincide with the prompt, so don't you worry.
