Toadkiller Dog appeared to be a big white dog with red eyes and taste for beer. The Black Company met it during their stay in the Plain of Fear. The dog and his partner, a muscular man known as Tracker were sent to deliver a message for Croaker.
The two spent some time with the Company and joined their military operation in the city of Rust. During the retreat from the city Toadkiller Dog was left behind. Tracker became irrationally upset after losing his friend. Fortunately for him the dog managed to return to the Plain of Fear by itself and was found by Croaker.
Croaker also took the dog and its owner on their next mission, which was in the Barrowland. There they were arrested there and had to break out of prison. During their escape through the Barrowland's forest Toadkiller Dog intercepted the chasing soldiers and killed over a hundred of them in the fight.
Later Toadkiller and Tracker return to the Plain of Fear once again. There the dog attacked The Lady, but Old Father Tree intervened. Toadkiller Dog's true nature was revealed: it was a demon in service of the Dominator. Afterwards the demon returned to his master in the Barrowland, in order to guard him against enemies. In the Battle of the Barrowland, Toadkiller Dog fought for his master, but lost one of his legs and was forced to retreat.
Later it returned to the battelfield and spent many nights digging something, which turned out to be a severed head. Toadkiller forced the forest shamans of a nereby tribe to create an artificial body for the head. The resurrected creature was actually Limper, who was intent on seeking revenge for his murder in the battle. He and the dog lead a small army, which first consisted of the tribes, but as they were decimating all cities in their way more people kept joining. They sieged the Tower of Charm with 5,000 soldiers, but were unable to take it over. They pillaged Opal and crossed the Sea of Torments to attack Beryl.