The Yetis were a huge set of monsters that lived in the Alps. They were installed as guardians for Tyren Lament's cave.
They were described as "big and furry" by Valkyrie and they were indigenous to the alps. They were also called Kang Admi by many.
They were deadly. Skulduggery said, 'If you saw one running at you, it was already too late' and that they were strong, fast and fierce.