Dragon Thighbone Club
Melee Weapon, unknown (magic) (attunement optional)
- Damage: 1d8 B
- Properties: Two-handed
- Weight: 250.0 lbs.
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.
Source: Storm King’s Thunder p. 105