飛竜の牙 [hiryuu no kiba] or 'wyvern fang' in Japanese.
Final Fantasy XII
Buy: - (sell: 1,274 gil)
Use: Penetrator Crossbow & Time Bolts
Drop: Aeronite, Aeros
Steal: Aeronite, Aeros
Poach: Aeronite
Description: A cruel fang, worthy of the mighty maw within which it once stood. These evolved not only to deliver crushing bites, but also to withstand the wyvern's deadly breath.
Grimoire of the Rift

Buy: - (sell: 2,500 gil)
Use: Dragon Whisker, Last Letter, Tonberrion, Reverie Shield, Ninja Tabi
Reward: Wanted: Marksman x4 (once)
Type: Bone, Rank: ★★★
Description: These keen fangs are resilient enough to withstand the wyvern's fiery breath.
Final Fantasy Tactics S

Buy: - (sell: 500 gil)
Use: Dagger
Obtain: Fordo Region/Hot Rock Sands lv60+
Description: A very uncommon bone
Category: Item