Thom Kallor aka Star Boy was a Xanthuan hero that joined the Legion of Super-Heroes following the death of Kid Quantum, Xanthu's original Legionnaire representative. He did not get along with Leviathan, partly because he blamed himself for Kid Quantum's death and saw his replacement as a reminder of his failure as a leader.
In addition to his mass increasing powers, Star Boy temporarily gained several new powers following spaceship accidents including Kryptonian level and fire-breathing. However, he found these abilities difficult to control.
The planet Xanthu left the United Planets, Star Boy and his fellow Xanthuan Legionnaires, Kid Quantum II and Monstress worked hard to reveal that their planet's government had been deceived. They were shocked at the revealtion and decided to remain with the United Planets. Star Boy had a relationship with fellow Legionaire Dreamer.
- 103 Appearances of Thom Kallor (Post-Zero Hour)
- 6 Images featuring Thom Kallor (Post-Zero Hour)
- 1 Quotations by or about Thom Kallor (Post-Zero Hour)
- Character Gallery: Thom Kallor (Post-Zero Hour)
Legion of Super-Heroes member