“ Nearby is a region of many curiously shaped hillocks. Last week a tremendous storm washed one of these half away, revealing a strange shed made of concrete panels. Its long side is aligned east-west, about 4m by 3m and 2.5m high, with a flat roof slightly sloped down to the north . The double doors in the south side have murky glass panels in them, but nothing much can be seen from outside, although it looks a bit like the top of a staircase. Will you dare go inside? What will you find there, and what lies below?”
“ 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.”
“ A swamp witch that, when she dies, a huge black worm burst from her corpse and tries to burrow into the nearest living creature to use as a new host. If the the worm is injured in-between hosts smaller black worms swarm out of any wounds and burrow into anything living.”