Evil TransFormer, a member of the dominant evil faction in
TransFormers Generation 1 and several other series. (Known as Destrons in Japan; converted into Predacons for the Beast Wars series).
Most stories suggest they began as a rebel faction on Cybertron which invented arms for the first time and sought to control other
transformers in order to dominate the universe, although I find it more likely that they were actually the dominant faction from the start which gradually became more and more arrogant as their power increased. (This is more consistent with the fact that the Decepticons are in control and the Autobots are the rebels in nearly all the early
TransFormers stories set on Cybertron).
Hell-bent on interstellar domination, including on earth where they crash-land, the Decepticons attempt to seize and amass energy when and wherever they can, without any concern for other beings or for sustainability. Many Decepticons are also depicted as ruthless and malevolent entities in their own right, enjoying destruction and violence as a good in itself (although the attribution of such emotions to robots seems
problematic).
The Decepticon symbol is a purple face insignia looking similar to Soundwave's head. In the cartoons, they also always fire purple/magenta laser beams.
Led by Megatron and later by his reincarnated form, Galvatron; also in various media by other characters such as Ratbat, Soundwave, Starscream, Scorponok, Bludgeon, Thunderwing and Lord Straxus.
"The Decepticons are blitzing Autobot City. We're really taking a pounding.
I don't know how much longer we can hold out" - Blaster, in
TransFormers: The Movie.
George W. Bush is intent on a Decepticon-style oil grab in the Middle East.
That van is painted in a very scary way; it looks almost like it should be a Decepticon.