"Ability is so cold it freezes all regular Bloons for longer, including White, Zebra, and Camo, slows MOAB-class longer, and greatly increases the attack speed of all Ice Monkeys for the duration."

~ In-game description

Absolute Zero is the fifth and final upgrade of Path 2 for the Ice Monkey in Bloons TD 6. Unlike in Bloons TD 5, Absolute Zero's attacks are based upon the Arctic Wind upgrade instead of Ice Shards. Compared to the Absolute Zero's previous upgrade, Snowstorm, this upgrade comes with a much more powerful freezing ability that freezes and damages all bloon types for a full 10 seconds, and activating the Absolute Zero ability grants all Ice Monkeys on screen with +50% more attack speed for 10 seconds, and its ability cooldown is 20 seconds instead of 30 seconds. With this upgrade, there is no initial cooldown.

Additionally, its main attack can freeze up to 300 bloons instead of 100, it has +10 increased range compared to Snowstorm for a total of 40 units, it can directly attack MOAB-class bloons (but not freeze them), and all its freezing attacks can penetrate 4 layers instead of 2. When crosspathed with Permafrost, every attack to MOAB-class bloons will apply a 25% speed reduction on hit (including with the ability).

This upgrade costs $17,000 on Easy, $20,000 on Medium, $21,600 on Hard, and $24,000 on Impoppable.

[https://bloons.fandom.com/wiki/Absolute_Zero_(BTD6)]