Ruling over a city full of monsters isn’t easy.  It does help to be one yourself, but not everyone has that luxury.  There’s always a problem that has to be taken care of and at least half of your citizens are nocturnal and food for the other half.  Let’s not even get into the constant soliciting from adventurers who are out to make a name for themselves.  So, what is a dark warlord of evil to do?

1. Make strict rules about what people can eat.  If you allow the monsters to feast on each other then you won’t have much of an army.  Sure, the strongest will be on your side, but how long before they start fighting each other.  Eventually, you’ll be left with a single, overweight monster that is eyeing you like a free rib-eye.  Just set up a farm and maintain enough livestock to avoid the disaster.