Sometimes throws a flash bomb that stuns bloons in a large radius.
~ BTD5 description
Throws a flash bomb that stuns multiple Bloons.
~ BTD6 description
Flash Bomb is an upgrade for the Ninja Monkey. It was first released in BTD5. In BTD5, it is the third upgrade of Path 2, while in BTD6 it is the third upgrade of Path 3. They both cost the same on both games, costing $2340 on Easy, $2750 on Medium, $2970 on Hard, and $3300 on Impoppable.
Flash Bomb is the third upgrade of path 2 for the Ninja Monkey in BTD5. It can stun and pop up to 60 bloons. This upgrade is not recommended for popping camolead bloons, unless it's the only way on a daily challenge, due to the cheaper cost of the Monkey Apprentice, and the Monkey Apprentice's faster firing speed. It turns the ninja dark gray with a red bandana. It costs $2750 on Medium.
Approximately every 3 Shurikens that the Ninja Monkey has thrown, a Flash Bomb is thrown. This stays the same even when upgraded to Sabotage Supply Lines.
In BTD6, Flash Bomb returns as the third upgrade of Path 3. Instead of giving the Ninja Monkey a black suit and red bandana, the Ninja Monkey wields a red tusked mask. Each Flash Bomb damages and stuns up to 60 bloons. Flash Bombs deal 1 damage to all affected bloons, including bloons with Black Bloon properties. It costs $2750 on Medium.
Any effects that increase the pierce of the x/3 Ninja Monkey (such as the x/1 upgrade of a Monkey Village or proper Monkey Knowledge in BMC) allows the Flash bomb to explode multiple times, vastly improving this towers popping power and support utility by stunning and popping an incredible amount of bloons at the same time. Tested and confirmed in the steam version of BMC (which is the same as BMC Mobile).
For some, the stun effect is how the price is worth it, through, while not as efficient as Bloon Impact, it can hold off until the user can buy it. However, Bloon Impact needs some camo support while this doesn't need any.
In Flash, the bomb has a unique sprite. But in the mobile versions, the bomb sprite used for the Bomb Tower is used for this upgrade.
In Mobile versions of the Bloons TD series (BTD5 Mobile, BMC Mobile, BTDB Mobile), the Flash Bombs do not look like stun grenades at all, but they look like large 1500s-era-type bombs.
This makes the Flash Bomb especially useful in BTD Battles, as the opponent can send in camo leads on Round 12 (of course, that's just for starters. Other upgrades cost a lot less.)