Which Decepticon is formed by the Predacons (beasts) in G1?

The Decepticon formed by the G1 Predacons is Predaking.

Predaking is the combined robot created when the five G1 Predacons merge their bodies and abilities. The team consists of Razorclaw, Divebomb, Rampage, Headstrong, and Tantrum. Razorclaw functions as the group’s leader, while the others contribute animal-based forms and components to the enormous gestalt warrior.

The Predacons are a Decepticon combiner team built around predatory beasts rather than construction vehicles or humanoid robots. Their combination gives Predaking tremendous strength, endurance, and hunting ability. In the original animated continuity, he is introduced during the later G1 era and becomes one of the Decepticons’ most formidable combiners.

The main mix-up is with other combiner names. The Constructicons combine into Devastator, the Terrorcons combine into Abominus, and the Monsterbots combine into Monstructor. Predaking also appears in later continuities with a different origin: Transformers: Prime presents him as an individual ancient dragon-like Predacon created or revived through Shockwave’s experiments, not as the five-member G1 combiner.