Stone Bloon: Looks like a normal Bloon, but with orange stones around it. Piercing projectiles removes 1 layer of the stones, and damages the Bloon. Piercing projectiles won't damage Stone Lead Bloons, only take off a layer of stones, unless the projectile is capable of damaging Lead Bloons. Also, Bloonchippers cannot suck Stone Bloons unless it has the Heavy Duty Suction upgrade. A Stone Bloon takes 8 hits to be fully remove the stones. Sharp projectiles do normal damage, but other projectiles to 2X damage. This does not apply after the stones have been removed. This can also be stacked with other properties.
It is immune to any bomb, but glaives deal 2 damage per hit. To deal with grouped Terra Bloons, use Glaive Lord.
It has brown rocks all around, and they disappear when this tower is damaged, revealing a gray bloon. When it is popped, it releases 2 Ceramic Bloons. There are MOAB-class bloons in Round 70, and this bloon acts like a weaker MOAB in that round.