Owlbears

Owlbears were created during the Second Shaping as an ambitious attempt to Bioweave the immense strength of bears with the flight and predatory senses of great owls. The Wardens hoped to produce enormous flying predators capable of contesting the Griffins, Pegasi, Wyverns, and other aerial creatures employed by the growing empires. They were never intended primarily as mounts, though a Warden could certainly have kept one as a companion or favored beast.
The experiment never successfully stabilized around flight. The immense weight and power of the bear continually won out, and the wings were eventually lost entirely. What remained was an enormous terrestrial predator with a bear's mass and strength, an owl's head, exceptional night vision and hearing, dense feathering across its forequarters, and powerful hybrid forepaws equipped with great grasping talons.
Although they failed in their original purpose, Owlbears proved remarkably viable. Rather than destroy them, the Wardens released populations into the vast forests of the Naja frontier, where they quickly established themselves among the region's great predators.
Owlbears are primarily nocturnal hunters. Their extraordinary hearing allows them to locate prey through dense vegetation and darkness, while their feathered forequarters make their movements unnervingly quiet for animals of such enormous size. They often remain motionless while listening before suddenly pursuing and seizing prey with their taloned forepaws.
They have never been meaningfully domesticated, though individuals raised from a young age can become accustomed to particular handlers, and Wardens were occasionally known to keep them as dangerous companions. Wild Owlbears remain fiercely independent animals.
Today they are simply another reason outsiders are warned against wandering into the Naja frontier after dark. The Wardens failed to create a flying bear, but in doing so left the forests with something arguably more troublesome: an enormous predator that hunts on the ground like an owl hunts from the sky.