Tearulai

Tearulai was an intelligent, emerald longsword that was originally crafted by a powerful elf of Myth Drannor. It had a storied history within the dungeon-complex known as Undermountain, having played an important role in the lives of the wizard-apprentice Yinark, his wife Wyllow, as well as the green dragon Valdemar, who actually took the sword's name as its own.

History
The first known appeared of Tearulai was in the hands of a fighter who, along with their fellow adventurers, ventured into Undermountain and reached the level known as Wyllowwood. The group was ambushed by Yinark, one of the apprentices of the archmage Halaster Blackcloak, master of Undermountain. Before his own death, Yinark slew most of the trespassers and the sword remained within the woods. Halaster recovered Tearulai and found he, nor any of his associates, could destroy nor wield the emerald blade. Unable to find any use from the sword, Halaster hid it in the bottom of a pond within the forest domain of the druid Wyllow, near the bone-strewn lair of a pair of death molds. It was protected by a stone golem that was specifically created to function underwater and protect the sword upon its death.

After she killed her husband Yinark, Wyllow inscribed a poem in elven, detailing the story of Tearulai on a large moss-covered stone located near the pond.

At some point the before the Year of Three Ships Sailing, 1492 DR, the sword had been recovered from beneath the pond yet another adventurer. When this individual found themself in a battle with the green dragon Valdemar, they thrust Tearulai into the skull of the young dragon, but failed to slay the beast.

The malevolent dragon, which had been used as a guardian of sorts by the druid Wyllow, had a significant change of heart (or perhaps mind) after the intelligent sword became implanted within its head. The sword and dragon became joined and Valdemar began to refer to itself as Tearulai. While it was unknown if the sword's intelligence affected the dragon, or the two consciousnesses merged as one, this unification had a profound effect on its personality. From then on, the dragon Tearulai enjoyed a peaceful coexistence with Wyllow and became a harmonious presence within the ecosystem of Wyllowwood.