The Professor's Protege - Gigantoads

First Available: Chapter 3
Other Requirements: Complete The Professor's Protege - Yellow Frogs
Location: Old Lestallum
Rewards: 5,000 EXP & Moon Pendant

For this version of the quest you'll want to visit Sania at Old Lestallum, she'll be standing in the eastern most portion of the town - shown in the screenshot above. In order for Sania to be at this location you'll need to have completed the previous quest, The Professor's Protege - Yellow Frogs.

If you already have the Gigantoad Oil that Sania wants in your inventory, then you won't have to hunt any Gigantoads. You'll be able to talk to Sania again right away and turn in the quest, I was lucky enough to have this happen to me on my first play through. Otherwise, head over to the location marked on your map and hunt Gigantoads here until you receive the Oil.