Fireflies

The Firefly is a Special Agent that goes around popping bloons, And it can pop up to 2500 bloons dealing 10 HP of Damage (What'dya expect?) but doesn't affect Moab Class Bloons, And it's Cheap, only 150 MM,It is exclusive to the Fire Festival Mission but completing it with an A or S rank will unlock it for all stages

Firefly PRO
The Firefliy PRO is Unlocked after the Firefly is placed 500 times, It can pop up to 5000 Bloons.

You'll need 75000 MM if you want to earn that

A Requrement Achivement
A True Firefly Achivement Can Be Unlocked by Using only Fireflies to complete a Track