Ozzel is a servant of Rezo. She first appeared in Slayers Revolution as maid to Gioconda, who was assumed to be the owner of Hellmaster's Jar then, since she specifically said that her orders were to "guard the jar and its owner" in EP09 (Slayers EVOLUTION-R). Despite being human in appearence, she is actually an artificial human doll.

Like Xellos, Ozzel remains polite towards people no matter what happens, even if they are enemies. While her body is incredibly lifelike, her head pops off at times in a comical matter, revealing her true nature.
After the first encounter with the Slayers, Ozzel is ordered to summon the assasin Zuuma by Gioconda. After Zuuma failed to kill the Slayers and they pretended to be captured by Gioconda's henchmen, Ozzel allowed them to escape and told them about her connection to Rezo the Red Priest. However, when they arrived in Gioconda's underground arena, Ozzel joined Gioconda and Zuuma and attacked the Slayers, saying that she had to do this as part of a contract. She then focused her attacks on Amelia Wil Tesla Saillune and Zelgadiss Graywords. When Lina Inverse was about to kill Zuuma with the Ragna Blade, Ozzel got in the way and was struck by the blade instead, and seemingly died as a result. However, in the 12th episode of REVOLUTION it is revealed that she, being a doll, was able to survive the gaping chest wound.

Ozzel reappears in Slayers EVOLUTION-R, her primary role being watching over the jar holding the soul of Rezo, especially after the death of Zuuma. She is very protective of it, and displays a great deal of affection towards the Red Priest. However, she is shown to display a blind rage towards other jars and smashes them on sight. When Rezo was revived in episode 11, she greeted him reverently, before her life-force left her, having served her only purpose in reviving him.

* An alternate transliteration of Ozzel is Ozer, which is "Rezo" spelled backwards.

(Source: Kanzaka Dex)