“ 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 weapon of war created by an extinct race, this rat appears normal but is a simulacrum - beneath it's mangy fur is a body of bronze. Commanded by words in a lost language, wherever it goes a virulent and lethal plague follows. The cure is similarly obscure.”
“ Pepperbox Wand
A typical wand with offensive capabilities (magic missiles, fire, fireball, lightning bolt) that was either damaged in combat or made just under par. When the wand is discharged, there is a 1 in 4 chance that it fires an additional 1d6 charges simultaneously or in rapid succession. Wands that shoot fire may incinerate innocents and friendlies, or burn whole buildings and even villages down. Those which shoot fireballs have a considerable radius, and lightning bolts that bounce upon contact with ground and stone can cause catastrophic random collateral damage. Those who have paid large sums for such a device may go seeking a refund, possibly even retribution.”