Astrotrain (Earth-1984)

Astrotrain is a Decepticon Triple Changer, able to transform into two different alternate modes; his being a train and a space shuttle.

Early Life
Astrotrain was a regular civillian on Cybertron prior to the war, who longed to explore the galaxy in search of new life and knowledge and was sick of the corrupt order on Cybertron. When the newly-formed Decepticons began their revolt that triggered the war, Astrotrain begged for mercy and was offered a place on the Decepticons if he wanted to live, which he painfully accepted.

Joining the Decepticons
Astrotrain was very regretful that he joined the Decepticons to save his own life, which made him cold and detatched. He often juggled the outcome if he didn't join, which worsened his morals and that he would be better off dead than cause any suffering. His partner, Blitzwing, proved to be his opposite because he actually wanted to fight.

Becoming a Triple Changer
Astrotrain, along with Blitzwing and Octane, reluctantly volunteered in an experiment conducted by Shockwave to create new soldiers, by altering the transformer's biology to be given an extra distinct alternate mode for counter defense. Astrotrain was frightened, while Blitzwing and Octane wanted the extra muscle. Astrotrain survived the experiment and chose a Cybertronian bullet train as his new alternate mode, as it was less hostile while also fast. He was also upgraded with a new body as part of the experiment.