Wrathbuds are first encountered on 19F in Etrian Odyssey II: Heroes of Lagaard. However, you can fight them on lower floors if summoned by a Rainbug. Wrathbuds are considered by many to be highly dangerous monsters. On top of their huge endurance, they have the Vine skill which not only is strong, but also has a high chance of inflicting instant death on the target. Also, with Unload, they are able to damage the entire party.