The Ay were dire wolves, a race of wolf-like creatures thought to have been extinct for a hundred thousand years. They were the ancestors of wolves in the Malazan Book of the Fallen series, although they were much larger than normal wolves. Baaljagg was described as the size of a hill-pony, at least two to three hands taller at the shoulder than the wolves of Blackdog Forest. Their snouts were longer and narrower than their modern cousins and they had sloping brows and small ears. Their canines were akin to those of a lion or plains bear and their broadly muscled bodies were capable of great speed and endurance.
The Imass tended to think nostalgically of the ancient wolves as they had sometimes hunted side by side. Tool said they felt responsible for the animals as the Imass had eliminated much of their natural prey through overhunting.
When the Imass took their vow during the Ritual of Tellann, they also brought the ay with them, as T'lan Ay. Pran Chole said the Imass had been selfish to include their faithful friends in their own curse. The change had stripped all that was honourable and proud from them.
In Memories of Ice
The female ay, Baaljagg, was a companion of Lady Envy, accompanying her on her travels from Morn to the lands of the Pannion Domin. She was the last of her kind having spent the years since the time of the First Gathering in a magical sleep created by an Elder God.
At the Siege of Coral, the T'lan Ay responded to the call of the newly freed Togg and slew hundreds of the Pannion Seer's Hunters who faced Onearm's Host outside the walls of the city. Afterwards, it was revealed that Baaljagg had been rescued by K'rul shortly before the Ritual had claimed the others of her species and tens of thousands of souls of the ay had been protected within her dreams for millennia. Onos T'oolan convinced Silverfox to finally free the T'lan Ay from the curse of the Vow and the wolves ran together with Togg and Fanderay in the dream world of Tellann.