Which of these skills was NOT obligatory for a ninja?

Those ninjas...no sense of humor. 😁

So, I guess that Stand Up Comedian was not one of the common professions for Ninjas to clandestinely impersonate.

I am sad to hear that Ninjas aren't known for their joke telling abilities. They always seem funny to me.

QuizzMan, humor is more of a non-Eastern requirement, such as for gunslingers and spies