Koitaru is a level 50 boss located in a sealed box at the Cursed Laboratory entrance. To spawn the boss you need either 25 (for 50% spawn chance) or 50 (for 100% spawn chance) DNA. This is considered the 2nd strongest boss in the game after Ieyasu. This is also the boss who drops the Kotsuzui Tanto.

It is currently the only passive boss entinty, meaning that unless you attack him he will not attack back. You can even lose it's agro just by simply cloaking away, making the battle even less harder.

But with the massive damage and huge HP he has, even a group of 4 highly skilled max level players can have struggles. Make sure to stock on pills, oils and medics.


  • He deals 325 damage per melee hit
  • Shoots bone spikes in every direction piercing players and dealing 178 damage for multiple hits
  • Shoots a wave of bone spikes piercing through players and dealing massive damage for multiple hits basically 1 shotting most players.


Drop Name Worth in Ryo Drop Chance Type
Ryo 300 ~10% Currency
Snake Belt - <1% Clothing
Kotsuzui Tanto - <1% Weapon
Blank Scroll - <1% Scroll
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