Medfant!Nimue Jakande had a LOT of tattoos despite never getting an official tattoo map. The most visible ones of them were a pair of eyes tattooed on her eyelids, signifying her "sixth sense"/"second sight". The rest of her tattoos would spell out stories in pictograms, meant to either ward off evil or call a purpose upon her.
Parable of The Cave is another one who has an excess of tattoos. Hers are made with a magical material called "glow" or "pure essence" which is permanently warm and glows in the dark, thus identifying her in the low-light conditions of her subterraneal home. Each tattoo has a meaning and has to be earned, spelling out the wearers occupation, marital status, feats age and even personality traits.