Dominus Trannis

Dominus Trannis is a Decepticon combiner from the 2001 Robots in Disguise continuity family.

Seen here after murdering the entire cast of Starlight Express.

Dominus Trannis is a villainous combiner, a taint on the legacy of the noble Rail Racer.

He is most often formed from:

• Astrotrain
• Steamhammer
• Cowcatcher/Loco

Fiction

Ask Vector Prime

Vector Prime brought up Dominus Trannis as an example of a combiner formed from Transformers with train alternate modes. He also explained that in most universes, Dominus Trannis was the result of Rail Racer being reformatted by the Robo-Smasher; in Viron 704.31 Epsilon, he was brought down by Defensor, who tried in vain to save the minds of his components. Ask Vector Prime, 2015/07/28

Notes

• An abandoned OTFCC 2004-exclusive redeco of Robots in Disguise Rail Racer would have been named "Dominus Trannis". While not the same character as the original Trannis, his name was inspired by that character. It's unknown what their team name would've been, perhaps the Astroforce? "Astrotrain" and "Steamhammer" were decided upon as names for two of the components and "Loco" was considered for the third. "Steamhammer" went on to inspire names for later official toy releases.