Inkwell, the Record-Keeper

Inkwell, the Record-Keeper, is an ancient dragon whose hoard consists of knowledge. Their lair is a labyrinthine library, the walls of each meters-tall, narrow tunnel lined from floor to ceiling with books, scrolls, stone slabs, and other written records. Like all of their world's true dragons, they're a shape-shifter - an ability they mostly use to become smaller, so that they can comfortably turn the pages of books, or hide undetected in places where they think they can learn something interesting. They don't breathe fire, but their tail produces a dark liquid which is almost impossible to wash off.

It is said that anyone who ventures into the dragon's lair without permission will surely forget how to find the exit, and be lost forever. Inkwell has been known to share their vast hoard of knowledge with humans, but only in exchange for offerings of "something they don't know yet." Such an offering is always written down in meticulous detail and added to the hoard.