Dimble Stumpwater is this worlds last best hope for expedient library book returns
a very useful exotic weapon
The PCs traveling through the mountain end up in the the small village of Bitterfruit, this tiny village is the epitome of paradise, but even paradise has its secrets.
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.