Insignia

One of the universals across all Transformers continuities has been the use of faction symbols to differentiate members of respective armies, and sometimes even sub-factions within armies.

Generation 1

Ancient Transformer

This is a symbol that Shockwave adopted in the G1 Dreamwave comic. Although Transformers have been split into two races, they are one species, he claims.

Autobot (comic)

In G1 Comic continuity the Autobot symbol was based on the face of the Last Autobot.

Autobot (cartoon)

In the G1 Cartoon it was derived from the Quintesson slave brand.

Autobot (ancient)

Autobot (War Within)

Decepticon (comic)

It seems likely that designers based the Decepticon symbol on the head of Soundwave's toy.
File:Symbol decept reg.jpg

Decepticon (cartoon)

In the G1 cartoon the usual 3D detailing of the symbol was interpreted as a third spike in the center of the crest.

Decepticon (ancient)

Decepticon (War Within)

EDC (cartoon)

EDC (Dreamwave)

Fallen

Optimus

Malignus

Quintesson

Ultracon

Used by Ratbat's group in The War Within era

Wreckers

Zarak Consortium

G.I. Joe Crossovers

Cobra

File:Cobralogo.gif

G.I. Joe

Generation 2

Autobot

The G2 Autobot symbol seems clearly based on Optimus Prime. In the Marvel Comics continuity this change may have occured since the Last Autobot had come and gone.

File:Auto-g2.png

Cybertron Alliance

File:Cybertron-federation.png

Cybertronian

This symbol was used by Jhiaxus's Cybertronian Empire, who considered themselves neither Autobot nor Decepticon.

Decepticon

The G2 Decepticon symbol seems to be a stylized, updated G1 Decepticon symbol. Bludgeon's Decepticons adopted this symbol around 1991, apparently unaware it was also being used by the Cybertronian Empire that they would soon encoutner.

Beast Era

Blentron

File:Blendtron symbol.png

Dinobot

Maximal

Maximal (Beast Machines)

Moon

Mutant

Predacon

Predacon (G1)

From IDW's Beast Wars comic books

Predacon (Timelines)

Worn by Razorclaw in Dawn of Future's Past.

Seacon Space Pirate
Vehicon

Robots in Disguise

Japanese Decepticon

Takara used this symbol, to represent the Decepticon (Combatron) sub-group in Car Robots- it's an upside-down G2 Autobot symbol, which had been molded into the Scourge toy, a redeco of G2 Laser Optimus Prime. The American version removed them, and used the traditional Decepticon symbol. Though it can be briefly seen in the cartoon, this symbol does not 'exist' in the American version.