The card artwork depicts a Ninja Monkey during the night throwing a spinning shuriken at a Camo Blue Bloon. It is set above a lawn with trees further away in the background.
Ninja costs the same as Tack Shooter with the same rarity and base ATK, however it has a second charge, detects Camo, but no Defender bonus. It's a strong early-game Monkey; it's cheap, versatile with its extra charge, and can defend against 0-delay Bloons.
The two Ninjas per card can allow them to alternate delays between each other, or use them together for a burst of damage.
Because it lacks a Defender bonus outside of having Dark Champion, it's generally advised to use their shots before ending turn when the opponent has 0-delay Bloons on your turn.
As with all Defenders, Ninjas can pop leaking Bloons even if there is a Must Pop Bloon on the field. They can also be used to soften up or pop Pink Bloons, with two Ninjas notably being able to pop one.
Two Ninjas have high enough burst damage to pop Blooming Bloon with Zee Jay’s Passive Awesomeness or an unscaled Steady Growth Bloon, making it powerful at dealing with Aggro. With one Zee Jay's Rad Enhancements, only one Ninja is needed.
Buffing Ninjas with Shinobi Tactics Ninja is highly recommended, as one Shinobi Tactics alone provides a total of +30 damage per turn and +60 burst damage when both Ninjas are placed.