“ A city is being plagued by a swarm of winged mice. The vermin can get anywhere, and they can easily avoid their normal predators by simply flying away from them.”
“ A known immortal traveling with the PCs kills an attacker, and is arrested and charged with murder, since immortals cannot kill in self defense, being immortal.”
“ 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.”