The Ninjas are the black clothed and masked people who enter the house.
Usually, they are the ones who deliver various things inside the house that are related to the tasks, twists or activities. They do not speak at all but they have the ability to climb on to the roof.
They usually appear at midnight when the housemates are asleep but on rare occasions, they can appear at any random time of the day whenever things are necessary to be delivered inside the house. They are also the people who fix things whenever something is broken inside the house.
The ninjas were first introduced in Pinoy Big Brother and was later adapted by Big Brother Australia when the series transferred to Channel Nine. Big Brother Naija also adapted the Ninjas into the house.
Throughout Pinoy Big Brother, aside from delivering things, the Ninjas also became more known for being involved in the tasks, often as the enemies of the housemates when it comes to tasks that require defense tactics.
- The Ninjas are basically just the Big Brother production staff who put various props inside the house. However, they couldn't speak to the Housemates.
- During Pinoy Big Brother: Double Up, Jason Francisco together with his male housemates from House A dressed up as Ninjas on the evening of Day 64 and climbed over to the House B to fetch Melisa Cantiveros for their private date in the House B's Outdoor Area.
- On one Occasion it could be a relative: In Jimboy's case. where one of the Ninja's dumps plastic on the activity area. where in later. the Ninja enters the area on a Finished Tricycle. and as Big brother commanded the ninja removes his mask. revealing as his father and Big BRother gives Jimboy at least 100 seconds.