Nimbul is one of many assassins in Baldur's Gate who tries to kill Gorion's Ward in return for the prize on the bounty notice that Sarevok has put up. In Baldur's Gate Chapter 3, after the player has cleared out the Nashkel Mines and is walking back up Nashkel, Nimbul will appear and hail the player outside the Nashkel Inn. He will wonder why he has been hired to kill the likes of you and attack. Killing him will get you 650 XP. Due to where he attacks, he may be quickly killed by the guards. In BG:EE, Nimble drops the unique scroll of Find Familiar.