Grooor is the first opponent faced by the Earth Team in Hostilities Break Out. Just as their two ships reach the finish line, the right engine of the Whizzing Arrow I explodes. Grooor is also caught in the blast, but neither he nor his ship suffers as much damage as the Earth Team ship and its pilot, Rick Thunderbolt.
Deprived of a clear-cut result due to the accident, Grooor wants to prove himself by beating the Earth Team in a rematch. He gets his chance in Grave Like Grooor, but the Human pilot this time is an inexperienced girl named Molly. Grooor drops down on Molly and Jordan and grinds them into the ground to accuse them of stealing his victory, and they shall suffer a humiliating defeat now. Grooor gives them 30 seconds for a lead, and Molly uses the extra time to engage the hyperdrive. Molly and Jordan leave Grooor behind, but the plasma tanks run out of fuel right before the finish line, so they must crawl to the finish line. Grooor closes in on them, but at the last moment, Molly turns the Arrow II around and Jordan fires at the joints on Grooor's ship, causing it to fall apart. The Arrow II crawls to the finish line, and the Earth Team wins.
After losing to the Earth Team, he seeks out Molly in In Like Flint and starts a fight with her in the tavern, intending to kill her. Though Jordan comes to help, it is Prince Aikka who defeats Grooor. He has no choice but to admit defeat and storms out of the tavern, never to be seen again.