A brash, young, tiefling (a person with fiendish heritage; one of Annah's grandparents was a fiend), Annah's alignment is chaotic neutral. She appears mostly human except for her tail. A fighter and a thief, Annah was raised by Pharod to be a capable rogue, useful for tasks that his more ordinary underlings could not complete. Utilizing push daggers she attacks her enemies when they least expect it. She has no tolerance for fools or the clueless. Skilled at Hive slang-laden verbal abuse, Annah piles it onto those who annoy her. She is somewhat superstitious, especially concerning the Lady of Pain. Found on the streets of Sigil very early in the game, The Nameless One only gets her in the party during the game's mid-portion. There she will automatically join the party after completing a task for Pharod.
In the loose novelization of the game by Ray and Valerie Vallese, Annah is similar in personality, but in many other aspects very different to her game incarnation. In the game, Annah's sole deformity is her tail. In the book, Annah is described as having beige skin, six functional fingers on each hand, thin black lips that barely frame her wide mouth (which is filled with a chaotic jumble of squared-off teeth and pointed fangs), white hair that covers her head like lamb's fleece in inch-thick curls, and slits of skin instead of ears. She also wears a tightly laced dark-purple bodysuit instead of the mismatching scraps she wears in the game. She also differs by being a multi-classed thief/wizard instead of a fighter/thief and by going by the name of just Annah rather than Annah-of-the-Shadows.
Annah is very acrobatic and dexterous so her outfit is light and made of leather. She has light arm and leg armor on one side which, combined with her agility, affords her better protection than full plate since this would hamper her movement. The armor is also somewhat mismatched since she is not particularly wealthy and probably acquired the pieces at different places and times in her life. The spiked shoulderpad is probably more for ornamentation and gives off an intimidating air. I would be dishonest if I didn't say the outfit is somewhat revealing partially to show that she is a free spirit and partially because it is appealing to me as an artist. Hey, at least I'm honest! Her weapons are punch daggers, which are basically brass knuckles with blades attached to them. So she has wild-west style holsters on her legs for quick-draw action.
—Character artist Eric Campenella
Gameplay-wise, Annah is a very useful ally as she is able to scout ahead of the party for any potential threats and traps, and she is able to deal an amazing amount of damage if she performs a backstab, which is extremely useful before fighting a boss or some very powerful creature. Annah is a potential love interest for The Nameless One. If the player manages to win her affections (which "just ends in a smooch"), they are rewarded with "a slight boost to her ability scores".
The character of Annah-of-the-Shadows was received very positively by the media and general public. Eurogamer gave this "streetwise young tiefling woman with a twitching tail and a sharp tongue" the Gaming Globes 2000 award in the category Female Supporting Character.GameSpot included her on the 2000 lists of the ten best female characters in the PC gaming according to the staff and readers alike.Tom's Hardware included this "savvy and independent thief" on the 2007 list of the 50 greatest female characters in video game history ("Annah is a true standout"), applauding her for her "witty, sexy personality," and adding that she could be played Kelly Macdonald in a live-action film. In 2012, gameplay.pl chose her as one of the 100 candidates to compete for the title of "Miss Games", where she was voted by the readers into the final round and finished ninth.