Not to be confused with Boomsday Weapon.

Boomsday Machine
Artwork from Super Mario Galaxy 2
Species	Fire Bar Tank Zap Nozzle
First appearance	Super Mario Galaxy 2 (2010)
Latest appearance	Super Mario Galaxy 2 (Nintendo Switch) (2025)

“My dad's gonna get angry if I let you get another ... Time to break out my Boomsday Machine! I'll just relax in my comfy cockpit and watch you go BOOM!”

—Bowser Jr., Super Mario Galaxy 2

The Boomsday Machine is a castle-like tank invented by Bowser Jr. that appears in Super Mario Galaxy 2 and its Nintendo Switch port. The machine has three Fire Bars circling around it, and the top section has a spinning turret mechanism that shoots balls of electricity like a Zap Nozzle. The machine is fought in the galaxy Bowser Jr.'s Boom Bunker. The music heard during this battle is the same as the battle theme against Bowser Jr. in Bowser Jr.'s Airship Armada from Super Mario Galaxy.

In The Super Mario Galaxy Movie, the giant cannon on Planet Bowser is referred to as the Boomsday Weapon, being named after the Boomsday Machine.

Battle

There are ample Cloud Flowers around the area to grab. The player must use Cloud Mario's ability to ascend the battlefield and get to the top of the Boomsday Machine. For the first round, the player must run for one of the updrafts and then spin to create a cloud and ride it upwards. From there, Mario or Luigi can traverse across the various clouds scattered throughout the battlefield, using his cloud-making ability to assist himself. Once the player reaches the top of the tower, they must damage the machine by ground-pounding the glass. If Mario stands on the glass cockpit for too long, Bowser Jr. will spin his launcher to knock Mario off.

The second round is much like the first, but now the tower attempts to vacuum the area, pulling the clouds out from under the player's feet. The player should still be able to just long-jump to the top of the tower in the same manner. The player also needs to watch out for an electric shield that covers Bowser Jr.'s dome periodically when he is sucking up clouds.

In the final round, the tower goes mobile. This makes the player's climb to the top more difficult, since Bowser Jr.'s cockpit is much higher up. The player still needs to avoid coming in contact with the yellow projectiles, the spinning fire wheel, and the vacuum attack. The fire on the Boomsday Machine also destroys the player's clouds. Once the player reaches the top of an updraft, they need to use the Cloud Flower refill to get to an even higher cloud tier. They should use long jumps to get to the distant cloud, and they can score another refill. From there, the player can reach the dome with their cloud platform recharge. Once the player arrives at the glass dome, they must ground-pound it a third time, which destroys the machine and reveals the Grand Star.

Mario faces this boss twice, with the second match being under a Daredevil Comet's conditions.

Gallery

• 

  Cloud Mario fighting the Boomsday Machine in its initial phase
• 

  Cloud Mario fighting the final form of the Boomsday Machine

Naming

The first part of the Boomsday Machine's name is a portmanteau of the onomatopoeia "boom" and the word "doomsday".

Internal names

Names in other languages

References

• Tanks
• Cannons
• Castles
• Towers
• Super Mario Galaxy 2 bosses