The Hiisi are a diverse type of humanoid enemies that reside within the mountain, and have a variety of different weapons and machinery at their disposal.
Dangerous machines, resistant to most damage, except explosions and electricity. They mostly guard The Vault, but can occasionally also be seen in Fungal Caverns.
Healers are comprised of a variety of Hiisi and robots, and generally will heal or provide buffs for any allies nearby. They consider most other non-player factions their allies.
All worms move through terrain, larger ones destroying a larger variety of terrain as they do. All of its blue varieties can rarely spawn anywhere within the mountain.
In Finnish, the word 'Hiisi' denotes a graveward or (more commonly in modern Finnish) spirit, that protects burial-mounds, much as the Hiisi of Noita seek to prevent the player from descending the game's mountain. Hiisi can also mean goblin or troll (though trolls may also be called peikko).
Most humanoid enemies will pick up wands that they walk past. If an enemy that is holding a wand in this way is kicked, the wand will fly out of its hands.