Decepticon. The Decepticons are a fictional faction of sentient robots in the Transformers multimedia franchise. Serving as the main antagonists in the franchise, their goals include conquering their fictional homeworld of Cybertron, defeating the Autobots, and achieving universal domination.

Description
They are depicted as a faction of sentient robotic lifeforms led by Megatron, identified by a purple face-like insignia and they have red eyes (while the Autobots have blue eyes). Capable of transforming into alternate forms, these are often high tech vehicles; including aircraft, military vehicles, heavy equipment, ground combat vehicles, expensive luxury cars, sports cars and even smaller-than-human-sized objects.

In the Japanese version of the franchise, the Decepticons are called Destron or Deathtron ( Desutoron). The only exception to this naming convention is Car Robots, where the sub-group referred to as "Decepticons" in the Robots in Disguise adaptation, is known in Japan as the Combatrons (the Japanese name of the G1 subgroup known as the Combaticons).

As opposed to the Autobots' Supreme Commander, the Primes, the Decepticons' highest ranking leader is often given the title Emperor of Destruction in Japan. Beginning with the original Generation 1 cartoon, the Decepticon rallying cry has been "Decepticons attack!", as well as "Transform and rise up!" in Transformers: Animated as a play on the Autobots' "Transform and roll out!" rallying cry.

Recurring members
Megatron: The arch-nemesis of Optimus Prime, he is often the leader of the Decepticons and main antagonist in most incarnations,he originally turned into a gun but later versions have him turn into a tank, jet or helicopter. 
Galvatron: The arch-enemy of Hot Rod and Ultra Mangus, Galvatron is a cruel and deranged leader of the decepticons he is often the upgraded from of Megatron but some later versions made him into a separate entity from him. His altmode was a moving cannon but later alts have him as a jet or tank like Megatron
Starscream: The leader of the Seekers and a power hungry traitor trying to overcome anyone who gets in his way. He turns into a jet.
Soundwave: The  communication officer he is the loyal minion of Megatron his alt mode was a cassette player but later versions give him a van or jet mode.
Shockwave: A purple Decepticon with one eye he serves as the scientist obsessed with logic. His alt mode was a futuristic gun but later continuities turn him into a tank or jet.
Blitzwing: A triple changer with a tank and jet modes.
Airachnid: A sadistic female Transformer with spider like features and a helicopter mode.
Nightbird: A female ninja who debuted in the original series as a human-built robot that is reprogrammed by the Decepticons, but later appeared in recent versions with a car alt mode.
Sideways: A spy with the ability to disguise himself.
Blackarachnia: A female Predacon who appears in the Beast era appearing in other mediums with a spider-alt mode.
Barricade: A ruthless decepticon soldier who takes on the police car as an alt mode.
Cyclonus: A noble warrior serving as Galvatron's right-hand man in some versions his alt mode is a jet.
Scourge: A ruthless hunter who leads the sweeps and turns into a ship. He is sometimes an evil version of Optimus Prime.
 Bludgeon: A Decepticon pretender who debuted in the comics and took over leadership. His alt mode was a tank.
 The Fallen: Megatronus Prime, one of the Thirteen primes, often turns evil and inspires D-16 to become Megatron and lead the decepticons sometimes. His alt mode is tank expect for the Revenge of the fallen movie where it was a jet.
 Lockdown: A bounty hunter who sometimes affiliated with the Decepticons his alt mode is a car.
 Scorponok: A large decepticon headmaster who serves as one of the leaders of the decepticons in some versions. Other versions of Scorponok varies to simply be generic mooks or a small transformers.
 Trypticon: A large kaiju sized Transformers who turns into a city.

Other Relations
Quintessons-a techno organic race who is sometimes allies to decepticons or enemies to both them and Autobots
Unicron- The Chaos bringer and the evil twin brother of Primus. He would often have Decepticons as his heralds.
Nemesis Prime- A clone of Optimus Prime with none of the Morals though he is sometimes depicted as an independent villain from the Decepticons.
Soundblaster- Originally an upgrade version of Soundwave, later versions portray him as a separate individual usually associated with the mercenary faction.

Factions

There are different factions of the Decepticons:

 Insecticons - A group of Decepticons who have insect forms and reproduce through cloning, with the clones often serving as expandable drones.
 Constructicons - A group of Decepticons who have construction vehicle forms. They are often shown combining into Devastator.
 Stunticons - A group of Decepticons who are made up of Cybertronians who can assume car form and one who can assume a truck form. They are often shown combining into Menasor.
 Combaticons - A group of Decepticons who have military vehicle forms. They are often shown combining into Bruticus.
 Predacons - A group of Decepticons who have animal forms. They are often shown combining into Predaking. The Predacon name was used for the main villains in Beast Wars: Transformers and Transformers: Robots in Disguise.
 Terrorcons - A group of Decepticons with monster forms. They are often shown combining into Abominus. Later versions are used to be related to Unicron.
 Seacons - A group of Decepticons with aquatic forms. They are often shown combining into Piranhacon. Five of the Seacons also have a third Targetmaster mode; when forming Piranhacon, the leader forms the torso, four others form the limbs, and the sixth will usually become a gun for Piranhacon to use.
 Horrorcons - A pair of triple-changing Decepticons with jet and beast alternate modes, both of which have Headmaster partners.
 Vehicons - The foot soldiers of the Decepticons. The Vehicon name was used for the main villains in Beast Machines: Transformers.
 Duocons - A pair of Decepticons whose alternate forms are actually split into two separate vehicles, a flying one and a ground one, which combine to form the robot.
 Seekers- A group of Decepticons led by Starscream with them serving as the flying armada.

Depictions in media

Transformers: Generation 1

The original animated series depicts the Decepticons as a malevolent faction of robots dedicated to the conquest of their home planet Cybertron. A war that lasted millions of years and soon that drained the planet of energy. The Autobots, the Decepticons' heroic rivals, chose to flee Cybertron in  hopes of finding more resources aboard their flagship the Ark, but were pursued by the Decepticons aboard their own warship, the Nemesis.
The two vessels clashed and the Decepticons boarded the Ark. In the ensuing struggle, control over the ship was lost and the Ark crashed on prehistoric Earth. Four million years passed before a tremor in 1984 reactivated the Decepticons, who assumed alternate modes based on Earth vehicles and technology and set out to conquer the planet and plunder its resources.
However, the Autobots were also reactivated and resolved to defend the planet and its inhabitants from the Decepticons' ill intent.

Transformers: EarthSpark

Under Megatron, the Decepticons originally fought the war on the ideals of creating a more equal Cybertron. With the war's expansion to Earth however, Megatron soon came to realize how far his faction had strayed from his original vision and joined the Autobots in hopes of ending the conflict. When Megatron seemingly destroyed the AllSpark in the final battle of the war on Earth, the Decepticons found themselves stranded on Earth as the SpaceBridge to Cybertron was destroyed along with it. For his actions Megatron was branded a traitor by many of his former soldiers such as Shockwave and Soundwave.

Stranded on Earth, Decepticons were forced to go on the run to evade imprisonment by G.H.O.S.T. and had to resort to stealing Energon. Even high ranking commanders such as Starscream found themselves becoming the prisoners of the Autobot-Human alliance. Many hapless Decepticons though found themselves working for the anti-Cybertronian scientist, Mandroid, as usually either mind-controlled slaves or as part of a deal to protect them from G.H.O.S.T.

While as prisoners of G.H.O.S.T., Decepticons such as Skullcruncher found themselves being unwilling experiments that left them severely weakened. When the Terran, Hashtag, inadvertently hacked G.H.O.S.T.'s security systems she ended up disabling the shields of the prison cells containing their Decepticon prisoners, leading to a short-lived prison uprising.

Many Decepticons found themselves participating in underground fighting rings known as "Bot Brawls" done for the amusement of their human audiences, the losers in these fighting bouts being chained to the ceiling and left to die. One of these being run by Mandroid who salvaged Cybertronian body parts from the losers for his own body modifications. Following another defeat by the Terrans, Mandroid rendezvoused with G.H.O.S.T. director, Karen Croft, where she formalized a partnership between them to begin constructing more Cybertronian control badges to use at her disposal, offering Mandroid the Decepticon prisoners under her watch as his test subjects.

Transformers One (2024)

In animation film, the Decepticons were formerly known as the High Guard, working for the original Primes. Led by their leader, Starscream, they know that they witnessed Sentinel Prime's betrayal long ago and have been seeking revenge ever since while remaining in hiding. After D-16 defeats Starscream in a fight, he becomes the new leader of the High Guard, after he and some of them are captured by Sentinel's guards. Some of the remaining High Guard are led by Orion Pax and Elita-1 to confront Sentinel and expose him for his crimes. In the face of this rebellion and Sentinel's death, the High Guard are led by D-16, now renamed Megatron, who orders them to destroy all Iacon. However, after their leader is defeated by Orion and renamed Optimus Prime, Megatron and the High Guard are exiled from Iacon for their war crimes and returned to their hidden location in the desert.

In the end, the High Guard are now renamed into the Decepticons by Megatron, in order to take control of Cybertron, starting the war against Optimus and the Autobots.

See also
 Autobot
 Maximal
 Predacon

References

External links

Extraterrestrial supervillains
Fictional characters introduced in 1984
Fictional con artists
Fictional extraterrestrial robots
Fictional vehicles
Fictional warrior races
Galactic empires
Robot supervillains
Supervillain teams
Transformers characters
Villains in animated television series