Can't get npc's to stay in zones

[jimbox114]

I followed the thread in the tutorial section of this site. I am trying to basically make custom mobs that respawn after a normal amount of time when killed. According to that thread you would basically:

#spawn Mob_name (and of course the numbers after that)
#npcspawn create
#npcspawn add

I did all this, and if I kill them they never come back, and if I #repop they never come back either. It says they was added to the database?

Also how do you change the actual look of a mob. For instance the default male froglok skin is that light green. I want to make a npc with the blue skin, how is that done? I have the guidebook, and have honestly been reading through the forums, but have not found alot of newbie friendly info on this.