This is how the Mutant tarn looks before he transforms.
Mutant tarns can be found deep in the Rellekka slayer dungeon. They are first an innocent Tarn of level 158, but transform into the much more powerful Mutant tarn when attacked. A thing to note is that the damage you deal to it before it transforms to a Mutant tarn does not carry over, so save that special attack. The tarns are not aggressive to players. Mutant tarns require 95 Slayer to kill, making them the highest slayer monster ingame. Without active membership players will not be able to damage them.
They attack with both Melee and very strong Magic attacks, it is advised to range them and use Protect from Magic to prevent taking any more damage than you have to.
