There are two stories to the Cursed Cup of Immortality, the one that was fabricated and sold to adventurers upon return, and the real story.
Warning: Trickster’s Tankard may result in alcohol abuse, random bar fights and very angry dwarves, half orcs, orcs, giants and anyone else who enjoys their drink.
Use with caution
The Yugzhee, or "hedgehog-people", guard a great, secret treasure inside their giant burrowed lair. The mysterious Wall of Keys, a 12'x10', foot-thick, cold-iron, "wall", upon which, on iron hooks, hang 100 ornate iron keys of all shapes and sizes. Each key opens some heretofore un-openable barrier, door, or gate, in the particular game world of choice.
The PCs have come upon a great boon, except for the fact that the keys cease to function properly if separated from the iron wall for more than a few minutes. Higher level characters will be able to figure out how to take the wall "with them" via magic. Lower level characters will have to get creative.