The Mad Huntsman, true name unknown, owns a pack of dogs at Stony Sept. He is a member of the Brotherhood without Banners, an outlaw organisation founded by Beric Dondarrion to bring justice to the Riverlands after it is attacked by the Lannisters. It becomes a center for war after Robb Stark arrives in the Riverlands, and after his father Eddard Stark's death at the order of the Lannisters' King Joffrey Baratheon, being proclaimed King in the North.
The Mad Huntsman lived in Stony Sept when the Lannisters attacked. His wife and sister were raped, his crops torched, half his sheep eaten and the rest killed, and six of his dogs were killed, the dog's corpses thrown down a well. The Mad Huntsman brings a flock of sheep to the famine-stricken Stony Sept. He catches some Northmen who took part in a massacre at Tumbler's Falls and hangs them in crow cages to die. Arya Stark gives them water and Anguy the Archer shoots them dead. A man says the Mad Huntsman will hear of this and won't like it.
After Ser Jaime Lannister escapes Riverrun the Mad Huntsman goes to track him. He captures Sandor Clegane "the Hound", whose brother Ser Gregor Clegane, "the Mountain that Rides", is among the Lannisters' forces. Before he can put Sandor in a crow cage the Brotherhood make him agree to bring Sandor before Beric. In a trial by battle Sandor defeats Beric. The Huntsman wants him put in a crow cage. However the Hound is released, though his gold is confiscated. With the gold the Mad Huntsman is sent to buy grain south of the Mander, accompanied by another member of the Brotherhood, Greenbeard.