Dreadbloon: Armored Behemoth

Dreadbloon is a boss bloon released on October 14, 2015. Unlike any other boss, it has lead property and is armored with yellow stone. It regains its stone layer for each boss HP level, regaining its shell a total of 4 times, including when it spawns. It is also weaker than Bloonarius and Vortex, giving the player an advantage to destroy it faster. It also takes extra damage from cannons, making cluster bombs a viable tactic to destroy it. Oddly, the stone armor is easily broken by anything with high fire rate and does not share the lead property of the boss bloon inside.