Spark

From Cths

The spark of a Transformer is the source of it's life and sentience. It is the third and most important of the basic parts needed to create a fully functional Cybertronian, the other two being their chassis and their programming. Without it, a bot would be considered no better than a drone.

Sparks cannot exist without some kind of housing. When affixed to a body, its usually located in a spark chamber, which in turn is usually located somewhere deep in the torso region.