Dropped from Minaruja (NM) in Abyssea-Grauberg, and is used to spawn Ningishzida (a hydra NM). You will also need a H.Q. Wivre Hide and Jaculus Wing to spawn this hydra NM.
The hydra NM drops WAR (up to 4), WHM (up to 2), SAM (up to 4), and BLU (up to 4) body seals, and Thicket Gages.
It also drops Atma of the Entwined Serpents and Venomous Hydra Fang key items.