“ A village where everyone goes blind sometime during puberty. What could be causing this? Perhaps something in their diet. Or some malignant gene. How would an entire village where only young childen can see function?”
“ The hammer of a war-god avatar, this massive weapon must be wielded by a giant or other supernaturally strong being. When struck against the ground, a massive seismic wave will propagate outward from the wielder subjecting all in its wake to a massive earthquake. This quake is strong enough to shatter castle walls.”
“ 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”