Created by writer Greg Pak and artist Ron Garney, he first appeared in Skaar: Son of Hulk #2 (September 2008).
[2] Following the conclusion of this series, he went on to feature in Realm of Kings: Son of Hulk by Scott Reed, with art by Miguel Munera.
[4][5][6] During the explosion that devastated Sakaar, Caiera used her Old Power to protect her womb, saving Skaar and Hiro-Kala from the blast, but landing them in fire.
He snuck out of the Fillian borders, and was stranded in a desert, where he was captured; he remained silent until a monster helped him and killed the two men.
Hiro-Kala helped the Surfer rescue the shadow slaves, while Yenrag was fighting the guards of Axeman Bone.
Skaar's pride caused him to waste time and to ignore the urging of his mother to evacuate the people of Sakaar.
[volume & issue needed] Hiro-Kala and the remainder of the Sakaarian people escaped in the last stone ship, though no one knew how it was to be piloted with no Old Power left.
While returning to the stone ship, Caiera revealed herself in a trail of Old Power, seemingly sorry for neglecting to care for Hiro-Kala in his time of need, instead reserving her counsel for Skaar.
After returning to the stone ship, Hiro-Kala killed one of Axeman Bone's soldiers for questioning his newest claim—he is the Sakaarson, the Lifebringer, and the World Breaker.
[volume & issue needed] Hiro-Kala, commanding the stone ship, followed Galactus's energies and landed on the planet Giausar, the first and proudest of the ancient Shadow's worlds.
Learning of his father's exploits there, Hiro-Kala attempted to conquer the planet, but ended up saving the dying world and pulled it out of the Microverse.
[9] As K'ai entered Earth's Solar System, Hiro-Kala mentally connected with his brother Skaar, alerting him of his coming.
[10] After the Hulk's forces made it through the starships around K'ai, Hiro-Kala was confronted by his father, the two finally meeting face-to-face.
[11] Hiro-Kala taunted his father by killing the remainder of the brainwashed children he sent to attack him, and revealed that he would make K'ai collide with Earth, destroying it and along with it, its Old Power.
During their battle, Skaar seemingly sacrificed himself to save a barge full of brainwashed slaves from a volcanic eruption.
[volume & issue needed] The Hulk, angrier than ever, beat Hiro-Kala into submission, but could not bring himself to kill him, instead reverting to Bruce Banner and stunning him with an old power taser.
When K'ai's Worldmind revealed to Hiro-Kala that the image of Caiera he saw was merely a figment of his imagination, he lost his mind, lashing out with the Old Power.
This allows him to perform various feats, including power bestowal, force fields, precognitive visions, energy blasts, mental control, technopathy, soul rescue, and spatial rifts.