They travelled in disguise to other territories to judge the situation of the enemy, they would inveigle their way into the midst of the enemy to discover gaps, and enter enemy castles to set them on fire, and carried out assassinations, arriving in secret.
In American and Japanese cinema/video games/cartoons, ninja are usually wearing black and move quickly and silently to dispatch their enemies and disappear without a trace and we thought this was cool. Apparently we were wrong and Canada is actually good for something besides ice hockey and Colbie Smulders, Ninjas.
This Halloween, I’m going as a Canadian Ninja. Take that Michael Dudukoff! Canada FTW!