Motormaster is a Decepticon who transforms between his robot mode and his tractor-trailer mode.  He belongs to a group called Stunticons named so because of their ability to perform stunts (which are sometimes dangerous to others) while in vehicle form.  He along with his four fellow Stunticons (Dead End, Drag Strip, Wildrider and Breakdown) combine to form Menasor the Super Warrior, Motormaster taking the position of his body and head. 

As the Stunticon Leader Motormaster is cold and cruel and longs to destroy Optimus Prime so he can become "King of the Road" (according to his Tech Spec).

The Generation 1 Motormaster, along with the other Generation 1 Stunticons, were released individually in 1986.  They were also available together in the Menasor giftset during the same year.