Bloontonium. The mysterious material that infuses Bloons with their power. Some would just wield it against their fellow Monkey Cities. The only viable deterrent is for you to join the arms race and build your own Bloontonium Generator.
~ "Precious Precious Bloontonium" Quest description
Full bloontonium

a full, second level, Bloontonium Generator

Bloontonium is the chemical used to create Bloons and is first mentioned in Bloons Tower Defense 5.

It makes its real appearance in Bloons Monkey City, and has as for now only one use, to send Bloons at other players in Monkey vs Monkey. It is created from Bloontonium Generators, and stored in Bloontonium Storage Tanks. Every time you win a defend battle, the amount of Bloontonium acquired is the same as how many Bloons you popped in that battle. Bloontonium can also be bought with Bloonstones for BloonstoneIcon1 per Bloontonium Icon40 (or BloonstoneIcon1 per Bloontonium Icon2 on mobile)


Depleted Bloontonium Dart unlock

Depleted Bloontonium Dart