First Appearance: Third season episodes "Once Upon a Time On Mars Parts One, Two, and Three"
Scabbard was Carbine's commanding officer during the Battle for the Tug Transformer. Afterwards, when the formal Martian government fell, he was a key player in helping the Freedom Fighters and Martian Army combine forces.
Wars Are Won By Those Who Dare series:
Carbine's natural talents at leadership soon catapulted her into the rank of general, but when Throttle was declared dead, Scabbard was the one she turned to for comfort. Their relationship soon turned romantic, and continued even after they learned Throttle was alive. She married him after she became pregnant with his child and finally reached the conclusion that Throttle was never returning to Mars (read Wars Are Won By Those Who Dare: Shatter Your Illusions).
Note that the readers were not introduced to Carbine's husband.