Bloog Ninja is sold from the Armor Shop in Battleon.
you talk to the healer in battleon, and go to trainers. there you talk to anyone and go to the buy armor shop. in that shop you can buy 6 different classes: warrior, mage, rouge, healer, ninja, and barber
You can be a ninja in adventure quest worlds but you have to buy the costume cuz you can't start as one you can get; the blood ninja armour or the ninja class where you can get ranks on classes
You buy from the ninja girl in greenguard west
greenguard west
you buy ninja amour from ninja in greenguard Forrest
buy a uniform
Improve You can buy the armor and if you want the regular armor then you take off your current armor :)
From quests, shops and events.
go to the man and buy it -_-
In Battleon,Yulgars Inn Bullsh@!@#*. you get it from the trainers of from ninja lady in greengaurd forest,
if you evil you can get it from the evil rep shop.
Go to the shadow of the wind village,at any store there buy itchy itchy paradise for 3500 gold and give it to Thyton. There you have it your ninja Armour.