Lava

Lava is a Road Item featured in BTD5D or BTD6! In BTD5D, it is unlocked at Rank 22. And in BTD6, it is unlocked at Rank 29. Place it on the track and it will burn up to 20 bloons. It costs 40 bucks in any Easy, 50 in Medium and 55 in Hard.

Trivia

 * The fire effect lasts forever!
 * You can still freeze or slow burned bloons!
 * The catch is that it removes slowing effect!
 * You can still slow it after that though!