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.
Sonic the Hedgehog CD
In Sonic the Hedgehog CD, Mecha-Bus can only be found at Metallic Madness . 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 Sonic Mania, Mecha-Bus appear as enemies. In terms of design, they look like their pristine versions in their debut appearance. In this game, they only appear in both Acts of Metallic Madness Zone.
In gameplay, the Mecha-Bus basically behave like in their debut appearance: they roll along the ground, raising and lowering their buzz saws. However, they are now more aggressive and faster than before. Also, upon destroying a Mecha-Bu, it will release an Animal.
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.