The Ninjina (Ninja + Vagina) is the mascot for the "Pussy Air Freshener," a cherry scented adult novelty product that you can display in your car, garage, or dorm room.
Phil: "Dude, it's pretty rank in here."
Jack: "Yeah, I wish the Ninjina would pay us a visit."
Phil: "The Ninjina?"
Jack: "Yeah, the Ninjina. He suddenly appears in a puff of smoke, and throws Pussy Air Fresheners like Chinese stars."
Phil: "He what?"
Jack: "You heard me."
Pussy Air Fresheners are an Adult Novelty Product designed to entertain both your visual and olfactory senses. They smell great and are sure to get a laugh from anyone with an open mind and a sense of humor. So hang one in your car, hang one in your locker, hang one in your home, hang one from your dick or your dildo. Just Hang One!
Carl: "Dude, what's that smell?"
Ted: "It's my Pussy Air Freshener."
Carl: "Where did you get that?"
Ted: "The Ninjina gave it to me."
Ted: "The Ninjina."