The Bigbom seems to be a giant version of the Bomb that first appeared in Sonic the Hedgehog (1991). They have large red and grey round body with red and blue buttons and a face plate with blue button that looks like its eye. On top of its head is a fuse that ignites once it sees its target. The Badnik is able to walk back and forth with pair of mechanic legs.
The Bigboms appear exclusively in Metallic Madness. They are placed on paths near tight corners or in wide hall sections, where the player can move behind the setting. Bigboms usually walk back and forth, but when one of them notices Sonic, it runs towards him while staring its self-destruction countdown. Like Bombs, Bigboms release six sparkling projectiles into the air when they explode. As the player has to advance through the Zone, kinky placements of Bigboms make it impossible to avoid them and dodging their projectiles can be tricky. Like Bombs, the player can also not destroy them.