According to DJ Jazzy Jeff, he saw DJ Spinbad perform a primitive version of the transformer scratch and was inspired to refine and develop it himself. As he says:
There was a guy in my basement at the time who said, "Wow, that sounds just like the Transformers when they open up."
The transformer scratch is performed by clicking the fader open and closed while moving the record forwards or backwards.
Wondering how this works? Check out the description.