Swarm (Transformers)

The Swarm is a creature in the fictional world of the Transformers: Generation 2 comic by Marvel Comics.

The Swarm is a large, amorphous, black mass of particulate sized, corrosive organisms that travel from planet to planet, seeking out cybernetic life forms. Upon contact with other life forms, the Swarm devours them, leaving behind only lifeless husks. Small portions of the Swarm can be destroyed, but it grows faster than anything can get rid of it. Energy shields have little effect on it, as it put intense strain on them until they collapse. The Swarm can also pick up small amounts of information from computers that it eats.

History
The origin of the swarm was revealed in the Generation 2 comic series. When the Transformers were first created by the god of light, Primus, they originally had the ability to undergo binary division, to split into two separate organisms. After the Cybertronian population reached a certain size, a command implanted by Primus caused them to lose the ability to reproduce and to forget that they had ever been able to.

At the end of the Great War, after Optimus Prime and Megatron had left Cybertron for Earth, a group of Decepticons also abandoned their home world for deep space. They went about conquering other planets and terraforming them into "little Cybertrons." At some point these "Generation 2"(G2) Decepticons rediscovered the process of binary reproduction and used it as a tool to expand their armies.

Each split produced a small flying mass of Cybertronian genetic material that was not unlike cancer. In low levels, the flying cancer dissipated on its own. Unfortunately, the use of the binary reproduction was far more regular than Primus had originally ordained. The cancerous by-product formed into a massive cloud, and eventually gained some appearance of an overall sentience, despite no true central intelligence. At this point, the mass of robotic organisms descended on various worlds, consuming all metallic and organic materials, leaving only dead husks behind.

The Swarm, after attacking and devouring several Gen 2 Decepticon groups, absorbed their last orders - to head to Earth. Jhiaxus's command to attack Earth undid the last chance of stopping the Swarm peacefully, which then proceeded to attack all combatants, whether G2 Decepticon or G1 Transformers, devouring Jhiaxus himself. Optimus Prime realised the only way to stop it was to purify it with the power of the Matrix and the peaceful intentions stored within. Prime willingly offered himself to it, and his desire for peace, along with the power of the Matrix, purified the Swarm of its aggressive intentions, giving it a purpose. The Swarm is last seen traveling off into space, having rebuilt Optimus Prime as a parting gift.

Trivia
It has been implied by Beast Wars story editor Larry DiTillio that the mysterious Vok from Beast Wars are an evolution of the Swarm, resulting from the power of the Matrix.