This red dragon's thighbone is 14 feet long, 250 lbs, and is wrapped in old leather, suggesting that it was once used as a giant's greatclub.
When you hit a creature of the dragon type with this weapon, it deals an extra 2d8 bludgeoning damage.
If you attune to the greatclub, it magically shrinks to a size that you can wield effectively.
This weapon requires two hands to use. This property is relevant only when you attack with the weapon, not when you simply hold it.