The Mecha-Bus resemble Japanese rhinoceros beetles. They have a blue body with two yellow, red-capped rear-wheels and two small grey forelimbs which have small black wheels with red caps for hands. On the front they have a black face with two black eyes, a yellow jaw cap and yellow helmet. Attached to their face is a horn with a buzz-saw.
Mecha-Bus can only be found at Metallic Madness in Sonic the Hedgehog CD. In gameplay, they roll slowly along the ground, raising and lowering their buzz-saw horns. However, they are unable to turn around, which makes them vulnerable to attacks on the rear. When attacking, the player has to avoid their buzz-saw.
In the Bad Future or sometimes in the present timeline of the Rounds, Mecha-Bus are one of the few Badniks who do not show decay, thus remaining pristine in appearance. However, such Mecha-Bus still cannot move their buzz-saws. Like every Badnik in the game, they are powered by Little Planet flower seeds which will pop out of them after being defeated.
- In an cinematic ending animation during the game's credits, the Mecha-Bus are seen residing in Wacky Workbench despite not appearing there in gameplay.