A horde of devious, ferocious, tenacious, and atrocious creatures, beasts, and monstrosities to populate the northern realms of your fantasy. Get them while they're cold!
A man is arrested for mass murder and found to be insane. Piles of corpses were found on his property, neatly stacked torsos with the skin peeled off and the limbs removed. The man readily admits the work is his, though he claims he was only chopping down trees, removing their branches, debarking them, and then stacking them to season.
The man may have swung the axe but it was a Druid who caused the delusion. This Druid is still on the loose and likely to repeat the crime. In time he may get more creative in his "punishments."