Constructicons

The Constructicons, so named for their group job of design, engineering and construction for the Decepticon forces, are particularly notable for their status as the very first combining sub-group of Transformers, able to merge their bodies and minds together to form the gigantic Devastator.

Devastator:
 * Head and Upper Torso: Hook
 * Lower Torso: Long Haul
 * Left Arm: Bonecrusher
 * Right Arm: Scavenger
 * Left Leg: Mixmaster
 * Right Leg: Scrapper (Leader of the Constructicons) (Currently not in Transformers Legends)

The Constructicons formed Devastator in the comics and cartoons, as of yet it doesn't seem like they can do anything of the sort in the game: Transformer Legends.