The Vok's History
The Vok are a mysterious race of energy-based aliens who transcend space and time, a highly-evolved species who reached an apex of technological sophistication as far beyond the Transformers as the Transformers are to humanity. Vast, cool, unsympathetic, and firmly committed to their enigmatic agenda, the Vok use primitive worlds like Earth as enormous laboratories to conduct strange and sometimes contradictory terraforming experiments intended to accelerate and alter the development of sapient life. However, these lofty goals rarely survive contact with the warlike Cybertronians, whose careless blunderings invariably contaminate and jeopardize the Vok's long-term ambitions. Although the Vok guard their secrets jealously, they rarely take direct action unless the situation calls for it. More often, the Vok will deploy autonomous weapons or a network of empowered proxies; in extreme situations, they may "sterilize" a failed experiment by deploying planetary superweapons.
Early into the Beast Wars, the Vok were alerted to the Transformers' presence. They abducted and scanned Optimus Primal, then returned him a day later, their business done. Later, the destruction of Brigadoon, the Vok's testing ground for any sentient life, sent a warning signal to them. Tarantulas immediately started to work on a way to escape the planet, darkly warning that it was doomed. The discovery of an alien Golden Disk would reveal he was right: The Vok were on their way and were not happy.
Once they arrived, they carried out further scans and briefly faced off with Optimus, taking the form of Unicron to do so; they claimed they had no physical form he could comprehend, and so were assuming the form of a "figure of authority" in his mind. They informed him that the Beast Wars had irreversibly contaminated their experiment and, due to unspecified danger if this was allowed to continue, they were going to cut their losses. The nature of the second moon was now revealed: It was an immense cannon designed to destroy the planet. Optimus Primal sacrificed himself in order to destroy the Planet Buster.
As a result of the Planet Buster's explosion, a quantum surge was released. The surge caused a mutation in several of the Transformers (notably, Megatron, Rattrap, Cheetor and Tarantulas) turning them into Transmetals. The destruction of the Planet Buster also released a transwarp wavefront that traveled through space and time, eventually reaching Cybertron in the era from which the Axalon and Darksyde crews originated.
Later, the Vok made another attempt to wipe out the Transformers. A second weapon, the Metal Hunter, appeared on the planet to knock the Transformers unconscious, and the Maximals Airazor and Tigatron were abducted. Megatron and Tarantulas, meanwhile, had both gained knowledge about the aliens from the Vok Disk. Megatron would go on to capture and alter an alien device he called the "Transmetal driver", which he used to create Transmetal 2's. It was also capable of resurrecting the dead.
Near the end of the Beast Wars, the Vok sent an emissary, Tigerhawk (a newly created fusion of Airazor and Tigatron), to Earth to deal with Megatron's disruption of the timestream. Tigerhawk was able to destroy the Predacon base, but was eventually subdued and captured by Tarantulas. Tarantulas was able to draw the Vok out of Tigerhawk's frame and into his own, but this led to his own destruction.