Krell

Krell are tiny, aggressive imp like demons. They are little threat on their own, but they have two things going for them. The first is that there is never just one krell. Their favorite tactic is to mob and overrun victims with sheer numbers. For this reason, whenever you see one, there are certainly more nearby. The second thing they have going for them is that they are harbingers of more powerful demons. Their very presence weakens the barriers between reality, allowing more powerful demons to enter whatever world they infest.

However, if you can isolate either one or a small group, they are basically useless. They can be taken out with bare hands, and do almost no damage on their own. They retain their aggressiveness no matter how many of them there are, but are only concerning in groups. One hit is nothing, but 100 can wear out even great foes.