Before you learn how to do this, please read how to start up PE.
OK after u have start up PE and Flyff, this is what you have to do..
1. Go out there and attack the mob you want prey on.
2. A Code will come out on the PE window. The code should be something like this, [MELEEATTACK] - 5E 38 P2 39 20 12 43 13 23 54
3. Higlight the code, in this case, it is 5E 38 P2 39 20 12 43 13 23 54, and press ctrl + c to copy it.
4. Paste it on the send bar by clicking on the send bar and press ctrl + v.
5. Move away from the mob that you were attacking.
6. Press send and wa lah!!!