Htebazile "Eizzil" Enived, a.k.a. Negative Numbuh 49(-Temporary), is the Negative Universe counterpart of Lizzie Devine and a member of the Destructively Nefarious Kids, working for Eeballaw as one of his most trusted agents. Her whole name is Lizzie Devine spelled backwards.
Since she is the opposite of Lizzie, she is very mean and evil. Even though Eizzil is the opposite of Lizzie they are both loud and bossy.
She captures her positive counterpart and lures Nigel to the Negaverse before knocking him out and bringing him to the DNK treehouse. Though Nigel and Lizzie managed to escape, Eizzil and Legin later recaptured them and went into the Positive Universe in order to pose as their positive counterparts and convince Numbuh 4 to take apart the Energy Enhancement Grid in Sector V's treehouse.
However Numbuh 4 was able to figure out that he was being tricked when Negative Numbuhs 2, 3, and 5 arrived and Numbuh 4 saw that Negative Numbuh 3 wasn't Kuki. Numbuh 4 manages to beat up Negative Numbuhs 1, 2, 3, and 5 and send them back to the Negaverse, however he manages to somehow convince Eizzil to see the error of her ways and assist him in stopping his negative counterpart's plans. When Eeballaw enters the positive universe, Eizzil tells him to get off her friend's world and kicks him back into the Negaverse.
After Eeballaw is captured, Eizzil rejoins the DNK in the Negaverse and assures the Postive Sector V and Lizzie that they won't need help from their positive counterparts now that nobody is afraid of Negative Numbuh 4 anymore. As Positive Sector V leave, Eizzil hugs Nigel for complimenting her eyes, calling him "Positive Nigie" before he's taken back to the positive world by Lizzie.