Tammi

Tammi first was featured in The Battle of The Labyrinth, acting as a cheerleader but turns out to be an Empousa. She was taught by Kelli, a senior Empousa. Because of the mist, both appear as cheerleaders of Goode High School. She has the ability to seduce young men, and then feed on their blood.

Appearance
Tammi is described hot and having blond hair and icy blue eyes when covered by Mist. She is shown to be an attractive woman since Percy was dazed at the way her hair swept over her shoulders and by her icy blue eyes. In her real state, her skin is pale white, with red eyes, has fangs and flaming hair. One of her legs is a donkey leg and the other is bronze.

The Battle of the Labyrinth
In The Battle of the Labyrinth, Percy first meets Tammi and Kelli when he was trying to get into the Goode High School via the back exit trying to avoid Rachel. Tammi was going to try and kill Percy right then, but the arrival of Paul Blofis stopped them. Later they tried to kill Percy, trapping him in a room with musical instruments with the mortal, Rachel. First, Tammi moved in a way that enchanted Percy. According to him, her eyes and the way her hair swept over her shoulders made him dazed. Tammi came close, but Rachel snapped Percy out of the seduced state he was in, but Tammi offered a kiss. Fortunately, Percy didn't fall under her spell again and he was able to kill her, but not Kelli, who was much more experienced than Tammi. She is said to be Kelli's trainee.