The Predacons are a faction of ancient dragon-like Cybertronians led by Predaking, once believed to be extinct.
The Predacons were once primordial Cybertronian beasts that went extinct in an event known as "the Great Cataclysm".
During the war for Cybertron between Autobots and Decepticons, Megatron sanctioned the creation of Predacon clones created by Shockwave. These Predacons were sent to Earth to wipe out any lingering Autobots and later protect the energon stores. While awaiting Megatron's arrival, the Predacons became extinct, forming the basis for much of human folklore. That was until Shockwave managed to clone the Predaking, which he brought to Earth to help Megatron hunt down the Autobots.
After the disastrous defeat at Darkmount, the Decepticons began tracking down fossilized Predacon bones through implanted microchips. It was Megatron's intention to create army of Predacons to destroy the Autobots once and for all. However, when the Predaking demonstrated sentience and offered to lead the clones, Megatron worried that the Predacons would eventually rebel against him and decided to pull the plug on Project Predacon. On Starscream's suggestion, they exposed Shockwave's lab to the Autobots, who then destroy it before the Predacons clones could fully awaken. The destruction of the clones in proximity to crates of synthetic energon fused their CNA to the synth-en to create cybermatter, prompting Megatron to ambitiously rebuild the Omega Lock.
In spite of the clones' destruction, Predaking reasoned that there were many bones on Cybertron for Megatron to clone.
Following the Autobots' revival of Cybertron, Starscream and Shockwave revived Project Predacons for the purpose of creating a new army to conquer Cybertron and avenge Megatron. Their first two creations were Darksteel and Skylynx. Meanwhile, Predaking made his home amongst a burial ground of unearthed Predacon bones.
At the same time the Decepticons located the burial grounds, it was also approached by Unicron in Megatron's body. After a brief tussle with the two Predacons, Unicron resurrected all the bones as Terrorcons for the purpose of destroying Primus, and therefore, destroying Cybertron itself. Predaking later returned and discovered the desecration. He was able to cement his position as Darksteel and Skylynx's king after a battle of dominance, before the Predacons went to assist the Autobots against Unicron at Shockwave's urging. Though the Predacons were unable to prevent the Terrorcons from entering the Well of All-Sparks, Cybertron was saved when Optimus Prime trapped Unicron's anti-spark within a reliquary of the Primes, causing the Terrorcons to disintegrate.
The Predacons later confront Starscream at Darkmount, intending to "settle old scores".