Thalantyr is a powerful mage from High Hedge. He lives in the High Hedge Estate, and sells you various magical items. To bring up the Selling Screen you have to talk to him a few times.
He lives a lonely life, save for his two enchanted Flesh Golems, that he keeps for protection.
Pickpocketing Thalantyr
Notes:
When playing the enhanced edition he is the fastest way to aquire a potioncase which costs 274gp.
Side quests
Buy and Sell
Even though he says that he is interested in buying magical items, Thalantyr will, in fact, buy pretty much anything that you are carrying except ammunition and some quest items.
† Possibly only in Baldur's Gate: Enhanced Edition
‡ These are powerful single-use scrolls, and cannot be used to learn the spells, where they exist, of the same names.