Uderfrykte Matron

A monster lurks in the high country in northeastern Cyrodiil. You get wind of the creature in a couple of places. The easiest to get to is Aerin's Camp to the southwest. From the camp, make your way northeast behind the rocks and you will soon find the body of Andre Labouche. On the body is a letter from Labouche's daughter that mentions a creature known as the Horror of Dive Rock.

Dive Rock is the peak of the mountain to the northeast. At the top of the mountain, make your way north to a rock strewn gully. Follow the gully southwest. Climb out of the west side at your first opportunity, follow the slopes west, and Dive Rock will soon appear on your radar.

Here on an icy sliver of rock, you will find an unoccupied campsite, a tent, supplies, and Agnar's Journal. The Underfrykte Matron has 500 hitpoints, Chameleon ability, and a 100 percent resistance to frost magicka. But she is just as vulnerable to fire as she is immune to the cold, and fire magic, plus an enchanted weapon, a weapon enchanted with fire magic will quickly be the death of her.

To find her, make your way back to the gully and follow it southeast to a rock strewn shelf. Here you will find the body of Agnar and nearby, the Matron herself.