BIO
If there's something to be done, Groundbreaker wants it done now, and he's more than happy to be the one to do it. This applies even when others don't ask nor want him to take action. Groundbreaker's always in battle mode, ready to open fire on an enemy position even before his comrades can figure out a suitable battle strategy in case of counterattack. This attitude carries over into his personal life, sometimes with negative results. Although he's friendly, he can also be brutally honest, blurting out unpleasant things that his friends don't really want to hear. He doesn't do it to be vindictive or mean; he's just not very tactful and has no time for misdirection. For Groundbreaker, the only way to go is straight ahead and at top speed.

WEAPONS/ABILITIES
Subject has great strength, which is augmented by his Pretender-shell. His shell's helmet has thermal and geological sensors, and the shell itself can emit a laser-shield that can block all but the most powerful energy attacks. In this mode, he is armed with an electron assault rifle that uses radar-targeting technology. He can also use a remote-controlled pulse cannon that flies and operates on its own. This is the primary weapon in his vehicle mode, which can reach speeds of up to Mach 1. In robot mode, he uses a standard energy pistol.

WEAKNESSES
Subject's laser shield is very draining on his Energon reserves. His thoughtless nature gets him into dangerous situations, including overusing his shield in combat.

Bibliography of significant appearances: Besides Landmine and Cloudburst most of the Autobot Pretenders made very few appearances in the Transformers Universe.
* (Marvel) Transformers #40 - Autobot Pretenders created by Scorponok Brainstorm and Highbrow.
* Groundbreaker made a few non-significant appearances throughout the ~2007-08 IDW comic "-ation" series.