[Melusine]

He's not unbeatable, but he does make mincemeat of your party pretty quickly unless you resort to cheesy tactics.

slight spoiler
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Run your party up to the other side of the small lake and put them on the wooden planks, then lure Drizzt into a fight with your toughest fighter character while the rest of your party waits at the lake.
Lure Drizzt all te way up to the side of the lake opposite to your party, then have them fire away at him with missile weapons while your fighter keeps running in little circles to avoid getting hit.
Cheesy though.