Board Thread:Guides/@comment-26297531-20150831072814

I recall a while ago someone asked on the Q&A forum about whether it's possible to farm for burst frogs. At that time i (being too sleepy) mistakenly replied it can be done on Monday's Karma/EXP dungeon, but that's for stat imps actually.

Well, most special vortex dungeon events have a rare chance of encountering and then a rare chance of capturing burst frogs. However, Hall of Melody, which comes whenever they open up all evolution vortex dungeons (which is at least once every month), has a pretty good chance of capturing Burst Frogs. This is because unlike other special dungeon events where you can only encounter Burst Frog in 1 of the fights only, it seems that Hall of Melody has the chance to spawn Burst Frog on every single fight (except boss stage of course). I just did 1 that had 3 spawns in 3 of the fights.

Thus, farming Hall of Melody for Burst Frog is a viable option to consider whenever the dungeon is open and you have spare energy to spend. There's also the same chance to capture Metal Gods. 