Well, I think you should start out by looking at a premade "mob" - Septavious. Just search through the xmls until you find him. Copy his xml code and paste it underneath and remember to change the type and id to something unique. After you are finished you should navigate to wServer > Logic > db > BehaviorDB.UndeadLair.cs and copy the code inside there. Make a new file in the db folder name it accordingly. BehaviorDB.{name}.cs and then once you are done, paste septaviouses code in there and change it to make it work with your "mob"