In my setting that is posted here called “The Kingdom of Orentia” the appointed ruler of the town of Thorpe is Griffin Orent. Griffin is actually the leader of a rather large group of bandits operating all over the kingdom. However, these are not your normal bandits…
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.