Zor

Zor was the leader and nerve-center of the Pescatons. He was larger than others of his kind, with an enlarged oval-shaped head, metallic scales and glowing emerald eyes. He had the power to hypnotize others.

In the 15th century, Zor brought the Doctor's TARDIS to the dying Pesca so that the Doctor could help his people find a new planet. When he refused, Zor faced him in mental combat and was defeated.

In the late 20th century, Zor led the Pescaton invasion of Earth, directing their attacks on London from his base in a sewer. The Doctor set a trap for Zor and the creature was subjected to high-pitched noise, killing him. (Doctor Who and the Pescatons)