There’s a fun article on Slate titled The State of the Ninja about ninjas in pop culture.
I, for one, never get tired of ironic ninja jokes–although to me the humor is not the ninjas themselves, but how funny the Western obsession with ninjas is.
It is the guy I knew in Junior High who had all the Chinatown-bought ninja weapons and loved to talk big about them; that archetype is why ninjas are funny. And really, the adolescent ninja fantasy echoes some of the role-playing that is inherent in any (especially any traditional) martial art. The tension that I feel between identifying with the twelve year old who wants to be special and rejecting that in favor of the more austere aspects of martial arts is what makes campy ninja jokes funny, at least to me.
Although whenever I’m in a sushi restaurant, I do always worry that ninjas are going to crash through the walls and kill me. I just can’t shake that feeling for some reason.