The Robot Beetles 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.
In Sonic Mania Plus’ Encore Mode, Robot Beetles sport a dark olive-green coating rather than their typical blue color.
In gameplay, the Robot Beetles 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 from 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, Robot Beetles are one of the few Badniks who do not show decay, thus remaining pristine in appearance. However, such Robot Beetles still cannot move their buzz-saws. Also, like every Badnik in the game, they are powered by Little Planet flower seeds which will pop out of them after they are defeated.
In Sonic Mania, and its expansion Sonic Mania Plus, the Robot Beetles returned as enemies and are referred to as Mecha Bus in the internal game files,[note 1] but are otherwise unnamed in any materials. In terms of design, they look like their pristine versions in their debut appearance. In these games, they only appear in both Acts of Metallic Madness Zone.
In gameplay, the Robot Beetles 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 Robot Beetle, it will release an Animal.
Powers and abilities
The Robot Beetles are quite fast, although not as fast as Sonic. They also possess a buzz-saw on their horn that they can use to rip through their obstacles.
In an cinematic ending animation during the game's credits, the Robot Beetles are seen residing in Wacky Workbench despite not appearing there in gameplay.