Very easy.
In "3D-Data" of the Rose Online Dirctory are all textures of animals, plants and so on .
1. Create a new Rose-Install
2. Go into the pbp directory
3. Go into 3 - Data, search for datas for Aqua-King
4. Copy and paste the textures of the Aqua-King into the Original Rose-3D-Data directory (the Aquaking file)
From now on, pbp will only attack the Aqua King.
I didnt try this way, but im sure, it will work.