1) Click on WoW Vendetta - Wage Your War
2) Name: Pick the Name of your Mob (e.x. - Stormwind Soldier)
3) Subname: put what you want his Guild to be (e.x. - Soldier of Stormwind)
4) Display ID: You will have to go on Thottbot or WoW, doesn't matter.
Thottbot way: Type in your wanted Creatures name (e.x. - Xylem) and then click on the correct 'Creature'. Now the Page URL for that mob should look like 'http://thottbot.com/c8379' or something close to it, with ####'s at the end. Now you want to CTRL+C or remember those numbers, then go to NPC Display ID Converter and type in the Code you got from Thottbot. Now a number should pop-up (e.x. - 7591) Now go and type that into your Display ID box on the Vendor Creator.
WoW way: Log onto WoW (You must be a GM / Admin) and find the wanted NPC you want your Mob to look like. Now ".npc info" on them and scroll up, looking for 'Display ID: #####' When you find that, the #'s after it are its Display ID, so you can just place them in the Vendor Creator and your done
5) Vendor ID: this is simply the ID that you will Spawn the Mob with (e.x. .npc spawn #####)
6) Level: make this the Level you want the Mob to be Spawned at.
7) Faction: there are 9 Factions to chose from, Stormwind, Ironforge, Orgrimmar, Darnassus, Undercity, Thunder Bluff, Silvermoon, Exodar and Neutral, which is the Argent Dawn. Choose one that you wish your Mob to be.
Health & Mana: this is what Health the Mob will have when it is Spawned, more HP gives it a bigger chance to not die if it is attacked. Mana is only if the Mob has a Spell placed in it.
9) Mount Display: This is for people who want Mobs on a Mount, if you know the Item Display ID of a Mount (e.x. - 2410 as the SW Charger) then place it in there, only if you know the Display ID of a Mount in-game. If you do not want your Mob on a Mount, DO NOT PUT ANYTHING IN THIS BLANK.
10) Click 'Submit'
11) On the SQL Query: find the Value for 'Faction', it should be one of these:
Change it from one of those to 14; The Faction for MonstersStormwind: 12
Ironforge: 57
Darnassus: 79
The Exodar: 1639
Orgrimmar: 29
Undercity: 71
Thunder Bluff: 105
Silvermoon City: 1604
Neutral Faction: 814
12) Download the Batch or CTRL+P into your DB Editor and Execute
13) It has been successfully added to your Server as a Mob!
Hope this helps! Good luck!
creds to blackboy