“ A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.”
“ The PCs discover a large white ball in the branches of a tree, or in a niche in a cave. Unless magically examined, or by a PC with a specialty in insects, it is a plain, smooth white ball. After a short time, it hatches and releases hundreds of spiders, cockroaches, some other nasty bug”