Fear Liath Encounter

[Death_Lord12]

For my the next encounter in my group I plan on the players fighting against a fear Liath. For those that don't know what that is, it's essentially a large humanoid mountain creature that hides in mist and uses fear effects to make intruders flee or cower so it can kill them.

I would need it to be around CR 15, but am not really sure where to start, anyone have any ideas?

[Thurbane]

Yak Folk (MM2) Dread Necromancer into Dread Witch or Nightmare Spinner?

[Inevitability]

Phaerlin Giant Zhentarim Soldier?

[Death_Lord12]

Yak Folk (MM2) Dread Necromancer into Dread Witch or Nightmare Spinner?

This works nicely, thank you.