Hardhead is a soldier to his core. A soldier with a stubborn streak a megamile wide. He's stubborn to the point of rejecting outright any path but his own, any idea that goes against his natural instinct or inclination (namely fighting), and any advice he didn't come up with himself. He doesn't talk much, and when he does, it tends to be blunt and terse, if not outright rude. A soldier doesn't waste time on social niceties when there's a war to fight.
Perhaps surprisingly, given his limited social aptitude, Hardhead has found a good companion in Duros, his binary-bonded Nebulan partner, who enjoys warfare just as much as Hardhead does. The two mesh so well, it's been said that theirs may be the best match among all the Autobot-Nebulan teams.
His alt-mode is a Cybertronian Tank.