Wyrmkiller

Sword effective against dragons.
Damage 19
Crit 11%
Hit +15%
Effective Against Dragon
Value 4,000 gil (4,000 gil on Easy)
Found In Mt. Duergar

Equipped By

Of the three family-killing swords found in Mystic Key-locked vaults, the Wyrmkiller is the best. Not only does it have 1 more Attack than the Rune Blade and Werebane, but the "Dragon" family is quite a bit more common than the Spellcaster or Werebeast families. This sword may have been better named "reptile killer" since it deals extra damage to lizards, snakes, and crocodiles in addition to everything even slightly draconic. It will serve your Thief well long after your Warrior and Red Mage have moved on to superior Weapons, and is an excellent midgame Weapon for all three Classes if you forego the Mythril Sword in Elfheim.
Compare Wyrmkiller to other Weapons
Treasures: Containing Wyrmkiller – 1 shown
Map
The specifics of where this treasure can be found
Notes
Mt. Duergar Found in a chest in the treasure room
Ice Brand Claymore

Related

Dragon Sword

Sprite
Damage 19
Crit 11%
Hit +15%
Val. 4,000 G

Equipped By

Found In Dwarf Cave
The Dragon Sword has 1 higher Damage than the other mystic KEY-locked specialty swords, but it also has a 2% lower crit rate.
The higher your Strength, the more important this difference becomes, making the Dragon Sword a better choice for THIEVES and RedMAGES than FIGHTERS. The Silver Sword is a superior Weapon for the latter Classes at this point anyway.