Cold Front

 is an upgrade in the Magic Monkey Knowledge tree. It increases freeze chance via Ball Lightning's ball itself from 25% to 100%. It requires 4 Magic Knowledge Points invested, Warm Oak unlocked, and a one-time purchase of 250.

Summary
Much stronger stalling by improving the chance of freezing to a full 100% guarantee. This converts the Ball Lightning into a freeze-stalling powerhouse, which combined with the stronger blowback from the already improved tornadoes makes for a significant boost in countering Super Ceramics.

Tips

 * 4-0-2 greatly increases the rate of producing lightning balls, and hence should be the preferred crosspath to make the most of it.
 * To make the greatest use of the guaranteed freezing, place the Druid such that it attacks along a straight line, so all bloons going along the line will guarantee to get frozen by the ball when touched.

Trivia

 * Cold Front was confirmed to have a chance in the Version 30.0 notes prior to receiving a buff.