Monty Tank

Monty Tank is the Monty Mole and tank boss of World 6 in New Super Mario Bros. The tank can be destroyed by Mario or Luigi stomping Monty's head three times, when his head is exposed. Monty's head is exposed when he comes out of the tank to throw Bob-ombs at the player. These bombs can be thrown at Monty while his head is exposed to cause damage. Each time the tank is hit, it will spin and quickly move back and forth along the ground. While doing so, it has an alarm sound go off and fires Bullet Bills from its turrets at multiple levels, depending on how many times it had been damaged. Each time it is hit, one more level is added to the tank, making it taller. Like the other bosses in the game, a ground pound counts as two hits; if Mario uses a ground pound on the first hit, two levels will be added, while ground pounding on the second hit will immediately defeat the tank. Mario and Luigi can also defeat it by just jumping onto the tank using a Mega Mushroom. The tank is invincible when Monty's head is not exposed. If the player stands on top of the tank, it spins back and forth to get them off it, while firing Bullet Bills.

Trivia

 * While internal data labels choropu (Monty Mole) separate from chorotank (Monty Tank), the Player's Guide attributes the name "Monty Tank" to the Monty Mole himself.
 * Monty Tank is similar to the Monty Mole enemies in Super Mario Sunshine, who similarly made use of Bullet Bill-shooting weapons and threw Bob-ombs.