Decepto-Pack
The Decepto-pack was a backpack designed to be worn by Humans. Upon activation it transformed into a full set of Decepticon combat armor for the wearer.
The armor consisted of a breast plate, belt, wristbands, Transformer helmet with faceplate, an arm shield, and pistol-style laser weapon. All pieces of the armor were visibly marked with the Decepticon symbol. The sheild also bears the likeness of an unknown Deception warrior. (Whether this face represented some autonimous Decepticon intelligence existing within the Decepto-pack is unknown.)
It is assumed that a human or group of humans outfited this way would be able to aid the Decepticons in combat with the Autobots. It is possible that the Decepto-packs were created to counter the Autobot's agressive S.T.A.R.S. program. It is unknown if the bearers of the packs would have been mind-controled conscripts or voluntary converts.
Toy
The Decepto-Pack was a sold by HG Toys in 1985. It's the only actually transforming Transformers costume marketed to the public. Why they chose the Decepticons over the Autobot is unknown, except perhaps that bad guys are just cooler.
The face on the Decepto-Pack sheild kind of resembles Cy-kill from the GoBots.
