Bestiary entry from the Clan Primer:
This creature always drops a trophy when it is defeated. This trophy is used in the Hunt Club side quest which involves trading in the trophies for items, armor and accessories.
|Common - (55%)||(Nothing)|
|Uncommon - (10%)||(Nothing)|
|Rare - (3%)||Antarctic Wind|
* The Gavial will only appear if you have closed the No. 10 Sluice Gate. Wait 10 to 15 seconds when you enter the area. Note also that the Gavial will only appear if you have initiated the Hunt Club side quest.