Ibis from MagnetBolt’s story “Mythic Dawn”.
 
“Ibis was most at home in the library. She could and had sat there for days at a time simply reading anything that caught her attention. Her routine was to pick a remote corner and turn it into her little temporary lair, only venturing out to find the most interesting prey. Ponies who disturbed her were given riddles if they wanted to borrow any of the books in the realm she’d claimed as her own.
 
Those that succeeded were given their prize, sometimes along with a recommendation on further reading if they were particularly polite company. The failures were also given their books because while Ibis was a monster she wasn’t the kind of monster who would keep a pony from the pursuit of learning. That would simply be needlessly evil.”