Neeshka is a tiefling rogue who is one of the companions available in the game. She is the second one to be encountered where she has to be rescued from a group of soldiers who have attacked her due to her tiefling heritage. When in Neverwinter she competes against a former associate who hates her for stealing his money. She is also hinted to be a descendant of one of the fiends in Ammon Jerro's abode.
She is confirmed to have survived the destruction of the King of Shadow's lair in Mask of the Betrayer. If the player is in a romance, then she will attend their wedding alongside Khelgar in the best ending.
Source: Wikipedia, "List of Neverwinter Nights characters", available under the CC-BY-SA License.