Set the system date to any day on
which a full moon falls and begin a game. The bonus
level is designated by a flag that contains a circle.
Experience
If you want your creatures to be
able to blow away any heros they need experience.
So I just put them in the combat pit with like 10
others and the victor will have gained atleast 2 levels.
Works best with a good creature (bile deamon) going
up against worse people (goblins).