Also, they do not despawn. When exploring the black forest early game, place a marker on the map for every troll and troll cave you find. Easy Troll leather when you are going to farm for it. I pinged every one of them, and like 12 hours later every single one of them was still there. They might have moved 50 meters away from the general location but they will be around. The only ones which despawn, are the ones spawned in by the "the ground is shaking" event. They will just pop out of existence right in front .