As the main villain of the franchise, Yzma is malicious and power hungry. She desires to become Empress and rule the kingdom, but is prevented by virtue of Kuzco having the position. Instead, she is first the king's advisor. However, she still attempted to act as Empress in his absence.
At the same time, Yzma is rather comically eccentric. She sees herself as the most beautiful person in the land, despite the fact that most people consider her hideous and often compare her to a dinosaur. When making plans to harm Kuzco, she often attempts to create overly complicated plans, before settling on a simpler version. However, she often fails to pay attention to minor details which results in her plans being thwarted.