“ 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?”
“ On a location with numerous webs, and at least one big spider, there is a something inside a cocoon. It is humanoid in shape, still moving. If the heroes free it (not before they kill or drive away the spiders), they meet a ... zombie!
The poor zombie wandered the dungeon alone, and tried to kill a big living creature (= a spider). The spider used the usual treatment, even if this victim did not look tasty. The zombie can be easily killed as any other zombie. It got but several doses of spider-poison, so can be something worth if it is extracted. You can mention to a druid or ranger the fact the spider had no poison anymore.”
“ A group of humans living in a mountainous area have spent generations mining, drinking home made liquor, and generally not spreading the gene pool around enough. The end result is a sub-race of humans who no longer have necks, rather their heads protrude from the upper portion of the torso between the shoulders. They have beards, and lacking the ability to turn their heads, can only see what they are directly facing. They are simple and to the point, and direct to the point of bluntness.”