Basilisk on the Loose

You get this quest from Nadarin. He's located in the Warehouse just south of Gantolandan's House in Baldur's Gate South East. Hell ask you if you can kill the greater basilisk that dwells in the northern warehouse in BG docks. To kill him you can use potion of mirrored eyes, protection from petrification spell or items that provide bonus to save vs petrification rolls, like Adoy's Belt, Claw of Kazgaroth or protection ring / cloak. After you have killed the basilisk speak to Nadarin again to claim your reward.

The basilisk also drops a Sphene Gem that can be used to complete the G'axir the Seer quest.