Rocky prided himself as the strongest member of Thirteen's Monster Party.
When he first met his Master, he was only seven years old.
Back then, he only followed the young boy because of Tiona, who could dominate snake-type monsters regardless of their form.
Rocky was a Rock Snake and spent most of his time deep underground.
But after that fateful encounter, he found himself mixed in all sorts of troubles.
Originally, he only planned to pay lip service to the human boy because he didn't deem him worthy to become his Master.
However, the more he spent time with Thirteen, the more he realized that the human boy wasn't normal.
No, he was abnormal.
A seven-year-old dared to scheme against a Majin Prince?
Not only was it a suicidal move, but it was also plain crazy.
Rocky had wanted no part in it, yet before he knew it, he found himself at the eye of the storm, unable to break free from the torrential wind that bound his fate to the boy whom Tiona recognized as his Master.
When the battle finally happened, he had wanted to escape. Even thinking of fighting against Arundel the Destroyer was madness.
But, as the monsters, whom he recognized as his fellow victims and were unlucky enough to become Thirteen's slaves, died one by one, Rocky felt something stir inside of him.
He risked his life to save the human boy, even dying in the process.
Just when Rocky thought that he had died, he found himself regaining consciousness within the chaotic battlefield where he should have died.
Since then, he, Giga, Blacky, Hercules, the Ogres, and Trolls had become Thirteen's Beast Companions.
They, who were powerful monsters themselves, chose to obey a person whose future had been nipped in the bud by a God who wanted the System of Cannon Fodders to understand what it meant to become a Cannon Fodder.
However, whether by the System God's design or not, Thirteen not only survived, but he also thrived.
So when they saw the Magma Bal-Boa rushing toward them like a flaming comet, they decided to abandon ship and jump away from the Death Worm.
Rocky's head collided with the Death Worm, making the latter skid dozens of meters from the ground before screeching in anger.
It then lunged at Rocky, slamming its entire body against the Magma Bal-Boa, sending Rocky's body flying backward.
Thirteen frowned, seeing that Rocky had ignored his order to fight the Death Worm only with ranged attacks.
However, he didn't confront or order the Magma Bal-Boa to stand down to follow his instructions.
He simply crossed his arms over his chest and watched through Tiona's eyes.
Rocky was smart.
Thirteen knew that.
But he also knew that even smart people would make stupid decisions from time to time.
He didn't know if Rocky was doing something stupid or not, but he could tell that the Magma Bal-Boa wished to fight the Death Worm in a one-on-one battle.
The main reason he didn't put a stop to it was because he could feel that something had shifted inside Rocky's mind, similar to gaining enlightenment.
Since the Magma Bal-Boa was putting his life on the line, Thirteen decided to respect his decision.
Currently, Rocky was being pinned down on the ground by the Death Worm, using its superior strength to overwhelm its opponent.
At that moment, when the Magma Bal-Boa was having a hard time against his opponent, he heard Thirteen's words inside his head.
"Go, Rocky," Thirteen said. "Knock his lights off."
The moment he heard his Master's voice, Rocky felt as if Thirteen's support and approval was the last push he needed to squeeze every bit of power from within his body.
Suddenly, the flames that coated his body blazed brighter than ever.
Rocky unleashed a Primal Roar at the same time the Death Worm unleashed its own.
Without caring about its enemy's flaming body, the Death Worm bit down on Rocky's neck, severing it completely from its body.