The Blast-O-Matic was a doomsday device King K. Rool attempts to use to destroy the Donkey Kong Island during the events of Donkey Kong 64.
This large laser cannon was designed by the weasel technician Snide, who is deprived of the weapon's blueprints and his membership in the Kremling Krew by K. Rool before the game begins. According to the blueprints, this weapon is composed for main computer, five reactors rooms and two bonus drums incorporated into mechanical "Crocodile Isle". This weapon was the K. Rool's plan B to destroy the DK Island (since plan A was K. Rool's brother called K. Lumsy after refusing this function).
To buy time to repair the weapon after the Crocodile Isle collides with a rock near the island, K. Rool imprisons Diddy Kong, Lanky Kong, Tiny Kong, and Chunky Kong and confiscates Donkey Kong's Golden Banana hoard. When K. Rool intended to activate the gun in time, Snide hack into the main computer by putting the timer after the Kongs recover his blueprints. The machine was shut off by 5 Kongs resulting the end of Kremling Krew's menace.
- The Big-O-Blaster (B.O.B.) from another Rare game Banjo-Tooie, is very similar to the Blast-o-Matic as they are both weapons of mass destruction that must be shut down as the primary objective of the game.
- Even after the Blast-O-Matic has been shut down, if the player chooses to quit after beating the game, the Game Over screen will still show K. Rool about to destroy DK Isles with the Blast-O-Matic.
- It is unknown as to how the Kongs can increase their time to deactivate the Blast-O-Matic by returning blueprints when Snide has no access to the weapon.
- If the player fails to claim the Banana Medals that powered the Blast-O-Matic before leaving Hideout Helm, they will be lost forever.
- This doomsday was sometimes nicknamed "B.O.M.".