|"Woods? What woods? There are few real woods in the Beyond and none near here."|
|— -The Whistler questioning Gwynneth in Spirit Wolf, page 136|
The "Whistler" MacDuncan is a male Dire Wolf (Canis dirus), and is the last skreeleen of the Blood Watch, formerly a gnaw wolf of the MacDuncan clan. He was a malcadh because of his crooked throat, which made him speak in eerie creaking whispers, but his howls are some of the best in the Beyond. He is one of Faolan's first true friends. There were rumors of him becoming a Blood Watch captain. He was a former Lieutenant and a skreeleen of the Blood Watch. But as of the latest book, Spirit Wolf, the Blood Watch is no more. The Whistler now resides in the Distant Blue with the other earthquake survivors.
The Whistler is a small, pale gray male dire wolf. He is very thin, since he had to eat last after twenty-five others in the Blue Rock Pack of the MacDuncan clan. He has a crooked throat, which causes his voice to sound like a strangled whistle. He has a hole in his throat, but when he howls, the air catches it just right to make it one of the most beautiuful of the wolves. During the Spirit Wolf earthquake and the destruction of Ember of Hoole, his throat is fixed.
He becomes best friends with Faolan while Faolan is on the trail of shame. Before Faolan enters the pack territory, he hunts and kills a lichen eater for the Whistler, the first real meal that the Whistler has had in a long time.
Although he is not mentioned, it was revealed in Shadow Wolf, that The "Whistler" was part of the byrrgis that was chasing Faolan. This is unusual because gnaw wolves aren't allowed to perform in a normal byrrgis.Faolan when doing penance on his way to one of the packs, the Pack of the Blue Rock, of the MacDuncan clan. Together, mostly Faolan, the two hunt down a lichen eater, when he tells Faolan all he ever eats is hare. Suddenly he admits to Faolan that he was apart of the byrrgis that chased him into the wall of fire and that he was sorry in doing so. It is noted by Faolan that the "Whistler" is the first wolf to be sorry for chasing him. After this, the "Whistler" becomes one of Faolan's first friends and participates in the gaddergnaw, along with Heep, Edme, Creakle, Faolan, and Tearlach.
Later, when Faolan begins to carve, he and other wolves are amazed of a melodious howl the "Whistler" sings for Duncan MacDuncan, as he had spotted the mist of the old chieftain. Other wolves soon join him in the grief for their old and wise chieftain.Edme, Faolan, Mhairie, and Dearlea, dying of starvation. Seconds after seeing his friends he collapses and falls into a delirium. They have him drink the blood of a snow hare to rejuvenate him. He manages to be grim and funny at the same time.The "Whistler" then joins them on their journey to the Blood Watch, where he later becomes one of the top skreeleens.
The Whistler first appeared at the Blood Watch. As a result of the Great Mending, he wakes up with a fixed throat and voice after the earthquake that destroyed the Watch, although he is confused at first, for he has a new howl, way of breathing, and voice. He finds Faolan with his sisters, Myrrglosch, and Edme in a crevasse. He becomes part of Faolan's Great Chain and helps Edme. He then joins them to on the journey to the Distant Blue through the Crystal Plain.