Dropped from Gargouille in Beaucedine Glacier {S} and Dire Gargouille from Xarcabard {S}.
Gargouille Spawn on the Top level Near the zone to Xarcabard. They have 2 Modes, a "Flying Mode" and a "Grounded Mode", During Flying mode they have Incredibly enhanced Evasion and access to Different TP Moves (Majority of which are AoE 200~300 DMG, Pretty weak).
During their flight they'll attack with Blasts of Energy from their hands (Almost the same as a Flying Wyrm), However, their attacks Still get Absorbed by Shadows and you can still Shield Block / Parry them.
On Ground form they have no special attributes.
Only use Triumphant Roar while on the ground.
Drop Rate seems about 1/4, Killed roughly 8 and ended up with 2, No Treasure Hunter
I think I would update that Droprate a little bit Asura. I fought them all night for 4-5 hours and got 8. I'am pretty sure you got pretty lucky. We had no TH at all 3 smn's just chaing them for some fun.