Poorly Cooked Karambwan is one of the Trolls fought during the combat portion of Troll Invasion. If you are adjacent to it when it "coughs" (about once every 3 seconds), your combat stats (Attack, Strength, Defence, Ranged, Magic) will be drained by 2 levels (which can be restored from the Supply Table). It will not retaliate unless attacked. Therefore, eliminating the rest of the trolls and keeping your distance from Poorly Cooked Karambwan before dealing with Poorly Cooked Karambwan is ideal, however, it tends to walk down the path leading up to the Death Plateau, where trolls will start throwing a barrage of rocks that cannot be blocked by a protection prayer. Attack him from a distance to lure him out or wait for him to wander back out.Ranged attacks are recommended against this troll for safer attacks.
The troll is named such because trolls are named by their mothers after the first thing they attempt to eat. This troll has probably eaten a poison karambwan, which is why he is poisonous.