The Warden of Marshwood Hill was a fully grown male heron who lived and ruled in the marshes near the Eastern Sea. He was known for being the law in the marshes and punishing his reptile subjects or "lawbreakers" very severely, sometimes eating them. His personality was easy to insult as he constantly referred to himself as "the law". He also hated fire.
He rescued Martin the Warrior, Rose, Pallum, and Grumm Trencher from a tribe of cannibalistic lizards after being warned by a dipper bird, then was saved from two slowworms, a grass snake, and an adder by Martin. After leading Martin the Warrior and his friends through the marshes, the warden promptly flew away. He showed up later in the battle against Fort Marshank.