The petitioner on this hunt is Gatsly. He can be found sitting just on the right of the board. Go talk to him.
Vulnerable to Wind
Cry for Help
You'll find Thextera in a small canyon south from the west exit from Rabanastre.
Its ordinary attack may cause poison and with the Cry for Help attack it summons to him more small wolves.
Attack Thextera from the beginning and don't bother killing the other wolves. It's good to use magick (e.g. Fire). If Thextera poisons one of your heroes use Antidote at once. And after you have dealt with Thextera take care of the other wolves.
Now get back to Rabanastre and talk with Gatsly in the "Sandsea".
Bounty: 500 gil, Headgear, 1x Teleportstone and possibility to buy Forgotten Grimoire in bazaar for 18 000 gil.