placing of monsters [Help pls]

Hello! Say please, how to place monsters in a game, where I need ? For example boss in town :) And that they did not disappear after implementation of server of restart. Many thanks !

@@"
it's the first time i see a topic a but someone spawn a mob a could not unspawn it

did you try to kill it ;)

because it wont be in a lua file or in database

I'll be nice and give you a hint server_init.lua :P