The Brambleblade

At first glance this wickedly hooked dadao looks like an oversized wooden sword. Indeed, it is made of wood, but wood grown from the roots of the immense enchanted oak known as the Brambletree at the heart of the Feywild.
It is imbued with Elven magic and was used by the Elven Dragonslayers of ages past to help drive Dragonkind from the forests of Yore. Its edge is razor sharp and its blade cannot be shattered by ordinary blows. Furthermore, upon striking a foe, vine-like tendrils sprout instantly from the sword and entangle its enemy, biting into their skin with wicked-looking thorns.
The Elves returned the Brambleblade to the Feywild for safekeeping, where it remains to this day under the stewardship of Prithvi, the Keeper of the Bramble.