Starscream is the Decepticon second-in-command who resents his leader Megatron and desires to replace him. Once Megatron leaves with Soundwave, Starscream takes over the faction and kills any Megatron-loyal Decepticons but realizes he somehow needs Knock Out as he is smart enough for ultimate resources and becomes Iron Man to escapes. Starscream then builds his own suit to kill Knock Out.
"Just because you have an idea, do you think it belongs to you?"
~Starscream, Iron Man
Starscream is greedy to be Decepticon and is evil as, if not more, Megatron. With Megatron and him taking leadership, he killed any of his teammates who stood in his way. After attempting to kill Knock Out and failed, he only needed his hated teammate because he was smart enough to miniaturize the Arc Reactor technology, if not Starscream would have killed him.
"How ironic Knockout! Trying to rid the world of weapon, only to create the biggest one of all!"
~Starscream as Iron Monger, Iron Man
Starscream is a silver robot with red optics and a red Decepticon symbol. Just like Knock Out wearing the Iron Man armor, Starscream retains his primary color(s) in the Iron Monger Armor. While he is sized normal like some Cybertronians, in his armor he is the size of Megatron who is normally larger compared to him. As Iron Monger, he has an Arc Reactor on the armor's chest that powers the suit. He is equipped with missiles on his arms in his normal mode and transforms into a jet, giving him wings on his back.
Without his armor, Starscream is a normal fighter Decepticon ready to fire with some weapons. He is also able to transform into a jet, able to fly fast enough.