Visser Three

Visser Three, born as Esplin 9466 Primary and later known as Visser One, is a fictional character and the main antagonist of the sci-fi book series Animorphs, written by K.A. Applegate. He is the leader of the Yeerk forces on Earth, having inherited the planet from Edriss 562, who was Visser One at the time. Sadistic and cruel, with a penchant for torture, he mainly inhabits an Andalite body during the whole series.

Visser Three has a personal feud with both Visser One and Elfangor. Several stories in the series feature the Animorphs using the Yeerk political situation to their advantage. However, they try to not let Visser Three look overly incompetent, fearing that he would be replaced by the far more dangerous Visser One. This is due to Visser One (before being replaced) favoring a subtle, quiet infiltration of the human population, while Visser Three favored waging open warfare on the humans in order to bring the campaign to a swift end. The Elfangor feud is revealed and ended in the first Animorphs novel, and its backstory is given in The Andalite Chronicles.