A rumour of the knights of some powerful king that sleep until danger threatens the kingdom.
The truth is that they were rebels, trying to split the kingdom. Once captured they were put into an enchanted sleep, protected from age and harm, until their aims have been carried out by others in which case they will awaken.
There is a loophole in the spell in that trying to take one of their weapons will also awaken them.
A dragon who demands to be told stories, if the person cannot comply, he or she becomes a meal for the dragon.
If a ghost possesses someone that had a different personality to them in life, the possessed body will slowly rot.
An Orc tribe that is relativly *gentle* instead of warlike.
A demon that feeds on good feelings, causing those around to feel upset or angry all the time.
Stinging nettles with a deadly sting that kills within minutes if the person who is stung cannot be healed.
A demon in human shape that murders travellers, however, he can only travel a certain distance from his home.One the adventures have passed that point, he is no threat to them.
There is a certain kind of silver-coloured spider who's bite injects an addictive drug into the person that creates a sense of euphoria. Once bitten the PC has a 50% chance of being addicted to the spider's bite and will carry it around with him or her.Long term use leads to serious injury or death.At first the PC will just seem a bit slower or sleepier then normal.
These magical boots empower the wearer with several abilities at once. Wondrous leaping, water-walking, and even flying! Yet the boots possess an insidious curse upon them as well. A deep and almost unfathomable (by others) feeling of listlessness, boredom, and even apathy affects the boots' wearer at all times whenever they are donned. Magic will not dispel the effects.
And so while the wearer of the boots can perform great feats of action during combat or at other opportune times and key moments, they'll never really want to do so, complaining "Meh, what's the point of it all anyway?" or "I would fly up and save us all guys, but sigh, maybe uhm, soonish, mkay? Bit bored by this whole burning tower at the moment."
Naturally the boots wearer's fellow PCs will grow quickly frustrated with this arrangement. There have been numerous occasions when one angry PC literally tears off the boots from his companion's feet in anger, and dons them in turn, only to immediately suffer from the same effects.
The solution lies in constantly "motivating" the boots' wearer with successful rolls, involving threats, flattery, fiery speeches, or even bribery.