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.
"Ladies and Gentlemen of Worth, please come closer and have a look... " In a little stand with numerous maps, the human Advantos sells land-rights with a shining smile and jovial talk at bargain prices. He sells even squatter rights (first to settle is the owner). About 20% of the lands do not exist or belong to someone else. About 30% do not have even that value, or have other problems attached- swampy, cursed, haunted, Old Indian/Pet Cemetery (tm)... Be assured you will not see this man in the same city twice.