The PCs have been traveling for a long time down the same stretch or round with no sign of anything suspicious. As they cross over to the next hill they see a gigantic splater of blood with a bleached dragons scull in the center of it. It the dragon skull's mouth is a tattered backpack with something wiggling inside of it.
A military organization, the Stalkers are a hunting/mining militia that are known for wearing full body shrouds that easily hide them in snow and other slushy terrain. The lightly armored warriors are known for the speed, stealth, and the vicious wounds inflicted by their hunting hatchets. Many of the Stalkers keep crop-eared warhounds with them, both for hunting, companionship, and in war.