“ 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.”
“ Orchound - A large canine with tusk like bottom teeth. Orcs bred these dogs to help them in battle by grappling with foes, and dragging them to the ground. Despite their fearsome appearance and loud bark, they are trained not to kill, this is the venue of the warrior, not his hound.”
“ A typical iron ore mine, the Irongate was closed some years ago and the entrance was closed off with a heavy gate of oak and thick iron bands, the Irongate. The mine itself was abandoned because it was a breeding ground for dire rats and many of the miners suffered from giant rodent bites as well as diseases from said bites. The mines are haunted by the ghosts of the men who died in dire rat swarms, adding to the mine's unpleasant character.”