Sand is a wise, but cynical eladrin moon elf wizard who owns a magic shop down by the docks in Neverwinter. He is a knowledge-seeker and is very interested in finding ancient relics and artifacts he can study and learn more from. He is a powerful and well-trained wizard, which causes him to often butt heads with Qara, who insults all wizards who have to study and read books in order to learn magic. He has a pet familiar cat named Jaral. It is revealed at the Ember trial by the Luskan ambassador Torio Claven that Sand was once part of the Hosttower of the Arcane, and if the PC has enough influence with him he shares a bit of his history. Sand had left the Hosttower after he could no longer stomach the things they made him do, and was marked for death. Seeking refuge in Neverwinter, Sand was tasked with being an informant for Lord Nasher, a position he does not relish.
In Mask of the Betrayer, he is confirmed to have survived the destruction of the King of Shadow's lair by transforming into an Iron Golem.
Source: Wikipedia, "List of Neverwinter Nights characters", available under the CC-BY-SA License.