A gruffian keeps stealing produce from farmers' fields outside of town. It has to be dealt with quickly--it's nearly harvest time!
This errand is available after defeating the Candelabracadabra on The Tombstone Trail.
Magmoiselle can be found at Old Smoky; head north at the first intersection to find her at the dead end with the broken robot. She's a unique creature that can only be fought during this bounty.
This battle isn't too hard if you give Esther her Drongo while you stay in control of Oliver himself and keep casting Frostbite. Magmoiselle will usually keep chasing after you, and although her physical attacks are quite powerful, keeping a distance isn't that hard. She also has a more powerful fire-based long range attack; defending against it works best.
Defeat it and you'll complete the bounty hunt, return to the Swift Solutions to claim your reward.