first, du need a folder with your Monster, extract the files from pack "monster" or "monster2.epk" folder and add in the XML with all types! than pack and put into "pack" folder.
extract the root.epk and open the npc.txt and input the New Monster
Code:
ID name of folder in the monster.epk
safe and pack
put the root.epk into your pack folder and summen the Monster with
your ID where in the Database
hope the post was helpfull :P
and my english are not so perfekt :S