Karmen

Karmen is a (presumed) Autobot from the Marvel portion of the Generation 1 continuity family.

You can't see me!

_{This character has no official visual representation in any Transformers product or media... yet, at least.}

Karmen is the sister of Autobot communications officer Blaster and Toaster. She transforms into a set of heated hair curlers.

Fiction

Blaster told a correspondent that he had a sister in addition to his brother. #317's letters page