The Decepticons are a fictional faction of sentient robots in the Transformers multimedia franchise. Description[edit]. They are depicted as a faction of sentient robotic lifeforms led by Megatron, identified by a purple face-like insignia. 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.