Frostfiend

“When the frost spirit saw he had lost the love of the princess, he rose up in great fury to destroy her. But Dazh was swifter and cut the spirit down with his blade and threw his body onto the earth. But the frost spirit was not dead. Lost in a terrible rage, he sought to destroy all the children of Dazh. We have lost many sons to his claws, and we will lose more.”

—Baba Olna

In the cities, the Frostfiend is thought to be mythical, appearing as it so often does in tales as the chief enemy of Dazh. But they are very real. Luckily, they make their home in the snows of the far north—and some scholars believe they are a part of those snows, as the Treemen of Athel Loren are with their forest. Due to their white fur, these bat-winged monstrosities are invisible amongst the blizzards in which they fly. Thankfully, they tend to shriek with bloodlust when their heat-sensitive eyes detect their next meal. This warning has saved many from being eviscerated by their razor-sharp claws, but many others remain rooted to the spot, for to face a Frostfiend is to face the terrifying fury of the blizzard itself. Few who survive such an attack ever go north again.

Source

 * Warhammer Fantasy RPG 2nd ED -- Realm of the Ice Queen pg. 136