Permafrost (BTD6)

"Bloons move slowly even after thawing out."

- In-game description

Permafrost is the Tier 1 upgrade of Path 1 for the Ice Monkey in Bloons TD 6. Like previous versions of Permafrost, frozen bloons move 50% slower after unfreezing, but this only lasts for one layer (2 with Deep Freeze, 4 with Absolute Zero). When crosspathed with any Tier 5 upgrade, including upgrading to Super Brittle, the Permafrost applies to blimps upon damaging, but with only a 25% slowdown instead of 50%.

It costs $85 on Easy, $100 on Medium, $110 on Hard, and $120 on Impoppable.

Appearance
This upgrade adds a snowflake symbol on the monkey's head. The portrait for Permafrost depicts the Ice Monkey blowing cold air.

Summary
Permafrost is cheap but somewhat unreliable way of slowing down bloons. As long as bloons pass by and are not hit by other towers, the Permafrost slowdown effect will last forever. This upgrade sees the most use in its effectiveness at slowing down Ceramics, especially Super Ceramics. When given to higher-tier Ice Monkeys, the Permafrost effect on MOAB-class bloons in effect clumps them up, slowing each affected blimp down permanently when hit.

Tips

 * Permafrost is a cheap upgrade to get to slightly boost the Ice Monkey's stalling potential. This has been utilized on harder maps for cheaply handling mid-game rushes such as Round 63.
 * Unlike Glue Gunner glue, the Permafrost effect lasts permanently but lasts for only 1 layer (more with middle path upgrades) instead of the default 3 for glues.
 * Permafrost can be added to Absolute Zero to clump up MOAB-class bloons.
 * Generally speaking, this upgrade is not very useful for Icicle Impale because blimps currently hit reduce to a halt anyway, unless no longer hit after a while.
 * The slowdown to MOAB-class bloons via any Tier 5 Ice Monkey's Permafrost effects is equal to half the amount of slowdown that Bloon Sabotage would deal. The slowdown is specifically 25%.

Trivia

 * Similar to its BTD5 counterpart's upgrade portrait, The official upgrade portrait for Permafrost in BTD6 depicts the Ice Monkey blowing cold air. In BTD5, however, a snowflake icon appears for the BTD5 Enhanced Freeze upgrade instead.