Mimic made of a unique metallic substance. Hunted on Ozmone Plain.
In order to find the Killbug the player must have spoken to the "Huntmaster" in Phon Coast and defeated Thalassinon, which will trigger the start of the Rare Game quest. The Killbug is then found on the Ozmone Plains in the area called The Switchback. It is located on the northern edge of the area near the entrance to Zertinan Caverns when the clock is between 10 and 39 minutes. It is pretty easy to spot as it does not match any of the other treasure chests found on the plains, and is larger than usual. This game is also a Trophy Game in that once it's slain, one can never find it again.