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.
The Macabre style of architecture is common in ancestor venerating societies, or societies that have been afflicted by a long term period of loss of life. The style is best noted for its use of a morbid and gruesome, skulls and bones, severed limbs and the like. It also alternately honors the spirits of the dead with stunning works of art, and mocks death through caricature and comedy. Macabre is the common architectural style in Ozea.