Mighty Biotron towered over the standard Micronaut figures, with room for one as a passenger in his chest beneath a clear canopy. On his back was a pair of tractor treads which enabled his built-in motor to drive him beyond his upright configuration's lumbering gait. His "boots" could be detached and become scooters.
Early versions of Biotron used a color scheme identical to that of its Microman precursor, Robotman.
Later, a dark tint was added to the canopy, the red of the front chest was darkened, and the weathered, muted blue of the "boots" was exchanged for a bright, smooth blue.