What do you mean, the little wriggly ones you throw at fish or the big rock ones that squish people?
"Is it just me, or is this cave moving?"
- Obin the Spelunker’s last words
To experience liberation in the arms of Goran, one must first await the coming of the Uroghi..
The Magma Borer is a large creature native to the extreme world of Crematoria. Scientists and planetologists have yet to be able to explain so many things about the planet and the unknown lifeform that made it possible.
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.