Machine Wars: Transformers was a half-hearted and unsuccessful attempt to parallel the popular series Beast Wars with a more classically styled Transformers series. Beginning and ending in 1997, the series' 12 figures was sold exclusively through KB Toys. It had no supporting fiction during its release.
The series was a mishmash of old and new molds, packaged and priced in a similar structure to the contemporary Beast Wars. Only four new molds graced the series, featuring Beast Wars design, like spring transformations, hidden weapons, and ball-and-socket joints. The four molds were used for eight characters, and the remaining characters were pulled from the European exclusive G1 toys of 1991. Even the package art was borrowed from previous toys, and subsequently edited and re-touched to look more like the toys it was used for.
Unsurprisingly, the series wound up clearanced out rather quickly, and generally forgotten about until BotCon exclusives and Timelines fiction referenced it in recent years.