This mini game can be played when Quina is in your party. Just head to a Qu's marsh and Go to the area with frogs. Quina will ask if she can catch some frogs, so say Yes. After catching so many frogs, Quale will come out and give Quina an Item. Below is what you get.
Sometimes frogs can be difficult to catch. Just keep trying! Also, if you catch all frogs, it will take a while for the marsh to populate again! Yes, the marshes get new frogs! So, it's best to leave a male and a female frog! That way more frogs will get there faster.
If you catch 99 frogs, Quale will challenge you to a quick battle!