Tapion vasalli
Tapion vasalli (listen 
) (lit. Tapio's Vassal, also known as Deer Boss or Island Boss) is a boss that can be found on the Lake Island (on the far west side of the map) after its prerequisite is met, which is hinted at via a statue on the island which depicts a sheep and 30 markings.
To spawn the boss, you must kill 30 helpless animals, and get within range of the statue, after which the boss will spawn from a blue portal. It doesn't seem to matter whether the animals killed are natural or from 
Polymorph, so an effective way to kill the requisite number of animals is by using Polymorphine on unsuspecting enemies, or with the Circle of Transmogrification spell.
If you killed more than 300 helpless animals and the boss, you can earn another Achievement Pillar.
Behavior & Combat
- When it takes damage, it deals 10% of the damage taken, multiplied by the amount of helpless animals killed, to you unless you have Polymorph.
- The boss cannot be blocked with Ambrosia, as the boss removes the
Protection from all effect every tick. - Surrounded by small ghosts similar to the Mournful Spirit perk that will do massive damage when touching you. They seem to move up and down around the boss fairly randomly.
- Fires out a large blue orb projectile that bounces off of terrain and lasts for ~1.6 seconds. When it is about to expire, it will halve the current HP of all creatures within 40 units. This cannot be blocked with Stainless Armour or Ambrosia.
- If any helpless animals are killed as the boss is near, its health will increase, which it will think is damage, dealing damage to you, which can be deadly. This also applies if you leave and load Tapion Vasalli in again.
Helpless Animals
- Counted: deer, duck, elk, scorpion, sheep, and Summon Deercoy spell spawns.
- Not counted: fish, and Flock of Ducks spell spawns.
Rewards
On death, it drops the Muodonmuutos spell.
All helpless animals explode on death.
Gallery
History
- Apr 8 2024: Added to the game.
