In the fourth season of the Generation 1 Transformers animated series, Headmasters and Targetmasters were introduced. Basically, certain Transformers were paired with a humanoid parter who "assisted" the Cybertronian from either inside their head (Headmaster) or their weapon (Targetmaster). I think the humanoid (I don't say human because most of the partners were aliens) wore a suit of armour themselves that transformed into the head or weapon of the Transformer, but I haven't watched that season for awhile (the show went downhill after the movie in my opinion)

~Hat~