The Big One Devastatingly large explosions, and each pops through 5 layer of bloons.
Cost: Easy: $8500 | Medium: $10000 | Hard: $10800
The Big One is the final upgrade on path 1 for the Mortar Tower. It makes the Mortar Tower generate giant explosions that pops 5 layers of bloons, pop black bloons and zebra bloons and have popping power increased to 100. It can pop black and zebra bloons because it uses Bloontonium.