Kokkol is a blacksmith in Final Fantasy IV, working in Kokkol's Forge. Although he was a great smith renowned throughout the Underworld, he becomes disheartened at ordinary commissions and refuses to work. Once Cecil brings Kokkol the legendary Adamantite ore, Kokkol becomes so excited he agrees to reforge Cecil's Mythgraven Blade for free. Once the party has acquired the Lunar Whale, Kokkol will give them the reforged Excalibur.
In Final Fantasy IV: The After Years, Kokkol has passed away, but one of his apprentices has taken on his legacy by offering to forge items. He is the namesake of the Kokkol Ore, which can be exchanged at the forge for new weapons in Rydia's tale.
In Final Fantasy XIV: Endwalker, a Lalafell named Kokkol Dankkol works in the Central Circuit in Labyrinthos, operating a forge named after him, working on the Aetherburner engine for the Sharlayan Forum. To improve the engine, he needs the Scions of the Seventh Dawn to gather refined adamantite, similar to what is needed to reforge the Mythgraven Blade in Final Fantasy IV.