At the start of the battle, Dumb Drum will attempt to smash Donkey Kong, and his buddy Diddy, by floating in the air and slamming itself down on them. If Dumb Drum misses the Kongs, it will begin to release enemies out of its body. It will release the following enemies; Kritters, Slippas, Klaptraps, Klumps, and Armys, in that exact order.
If the Kongs defeat these enemies, Dumb Drum will attempt to crush them again at a faster pace after each round. In order for the Kongs to defeat Dumb Drum, they must destroy all of the enemies it releases, which somehow affects it. In the Game Boy Advance port, the Kongs have to throw a TNT Barrel (which will appear after taking out the enemies) at Dumb Drum to damage it.
When defeated, Dumb Drum will self-destruct, giving Donkey Kong and Diddy Kong access to Chimp Caverns.