The Mighty Invasion of Buur, Saphyryan, and the Grey Earl!
From FlyFF WIki
They somehow ninja'd their way into Madrigal this week and not even Shade, Bubble, or Iblis know what they're doing on your lands! Regardless, the solution is clear! Your mission, should you choose to accept it, is to hunt and farm these baddies for some goody yum yum loot! They'll be around all week, and they should only stick around up until May 1st.
Don't let their surprise attack fool you, the game remains the same!
Happy hunting Flyffers and good luck! Enjoy the event.