Deceptcons (Transformers Prime)

The Decepticons are one of the main factions in the Transformers mythos. They typically deal with things like conquering Cybertron, defeating the Autobots, amassing large amounts of energon, developing powerful weapons, and beating people up. Not necessarily in that order.

Unlike the Autobots, whose leader is a Matrix-wielding Prime, the Decepticons are led by the most powerful of their ranks. This often causes some conflict, as Decepticons generally all think they are the most powerful.

Additionally, the Decepticons aren't exactly the most compassionate beings in the universe, but not all of them fight out of greed. More than a few have a sense of honor, while others believe that Cybertron would be better protected by aggressive expansion. While the name does a good job of demonizing them, it usually comes from a sense of being ironically evil or due to being labeled as such, as most members genuinely believe that their cause is just and the Autobots see them as the bad guys... or they're just psychopaths looking for an excuse to do what they do.

Ultimately, the Decepticons wish to protect their homeworld, even if it is at the expense of others. Usually.