The Garif Adventurer is an enemy in Final Fantasy XII and is the only enemy that can gain the player the garif in the bestiary. He is endemic and can only be found in the Greensnake area of the Ozmone Plain.
The player may also find other types of garif roaming this area, in Giza Plains (during the Rains), and just outside Jahara. These can be attacked and killed, but doing so won't add them to the garif file in the bestiary since they are treated as allies instead of enemies.
Garif Adventurer is arguably the most annoying enemy in terms of gaining his bestiary file, or completing it totally. He has a small chance of spawning on either the north or the west entrance to the Greensnake.
Garif Adventurer is docile and won't attack the party unless provoked, in which case he'll hunt the party down until they leave the area. This garif is hostile to the other enemies, especially the Wus, but not the Ozmone Hares, so he's probably present if there's a commotion in the area; therefore if it's a commotion he needs, the player should eliminate all Wus in the Greensnake and the Shred, then zone back and forth between the Greensnake and another zone until it appears, then go two zones away and repeat.