Cosmic Boy

Created by Mort Weisinger, Otto Binder, Curt Swan and Al Plastino

Cosmic Boy I

Rokk Krinn of Braal

Hu (father), Ewa Krinn (mother, deceased), Pol Krinn (Magnetic Kid, brother, deceased), Lydda Jath (Night Girl (wife), Pol Krinn II (son)

Legion of Super-Heroes

Adventure Comics #247 (Apr. 1958)
SW6 version: Legion of Super-Heroes vol. 4 #24 (Dec. 1991)
As Polestar: Legion of Super-Heroes vol. 4 #54 (Feb. 1994)
Retroboot: Action Comics #859 (Jan. 2008)

Original Cosmic Boy

Take a ride on his disco stick. From Secrets of the Legion #1 (1976); art by Mike Grell.
Take a ride on his disco stick. From Legion of Super-Heroes vol. 2 #297 (1976); art by Keith Giffen and Larry Mahlstedt.
Cosmic Boy's iconic "disco era" costume, designed by Mike Grell. From Superboy & the Legion #215 (1976); art by Mike Grell.
During vacation on Braal, Cos and Night Girl must help stop the Worldsmith. From Superboy & the Legion #236 (Feb. 1978); art by James Sherman Inks Bob McLeod.
Cosmic Boy is out for blood after learning of his mother's death. From Legion of Super-Heroes vol. 2 #297 (1983); art by Keith Giffen.
Rokk learns that his friends are contemplating leaving the Legion. From Legion of Super-Heroes vol. 3 #11 (June 1985); art by Ernie Colón and Larry Mahlstedt.
Profile picture from Who's Who #5 (July 1985); art by Richard Howell and Karl Kesel.

The planet Braal was known to the greater galaxy as early as the 20th century. The young Daxamite (and Legionnaire), Lar Gand, once met Krinn Magar. (Valor #20) Its humanoid settlers evolved within the planet's intense magnetic field. It caused them to evolve the power to maniuplate magnetic forces. This helped them ward off the native beasts, which were partly metallic.

In the 30th century, the planet was economically-depressed, and Hu and Ewa Krinn travelled to Earth to find work. Their first child, Rokk, was born there. The child's birth within Earth's own strong magnetic field made his magnetic powers stronger than that of the average Braalian. By age 13, he became a champion at the game of magno-ball (thought the Olympic championship eluded him). At 14, the mark of Braalian adulthood, Rokk followed in his parents' footsteps, and headed to Earth for work. (Secrets of the Legion #1, Legion vol. 2 #296) NOTES: Cosmic Boy's name and homeworld name and homeworld were revealed in Superman Annual #4 (1961). His parents first appeared in Adventure Comics #335 (Aug. 1965).

On his flight to Earth, he met Garth Ranzz. When they arrived on Earth, a young woman, Imra Ardeen, alerted them that their fellow passenger, the billionaire R. J. Brande was about to be shot! Rokk and Garth used their super-powers to disarm Brande's assailant. Brande was so impressed by their improptu teamwork that he invited them to form a new kind of law enforcement group: the Legion of Super-Heroes. Rokk accepted and took the codename Cosmic Boy. (Superboy vol. 1 #147)

Shortly thereafter, their computer selected him as their "optimum leader." (Legion vol. 2 #297) Rokk served as Legion leader during its first two years, helping to lay its formal groundwork, organize mission teams and recruitment efforts.

His fame reached the planet Kathoon, where youngx Lydda Jath became so enamored with Cosmic Boy that she asked her father to invent super-powers for her. She was rejected for Legion membership, though, and joined others to form the Legion of Substitute Heroes as Night Girl. (Adventure Comics #305)

As a "Sub," Night Girl maintained proximity to Rokk and made her feelings known to him at the first opportunity. (Adventure #311) They became a bona fide couple. Years later, Cosmic Boy briefly broke up with Lydda because she failed to make one of their dates. They repaired things and remained together after that. (Superboy vol. 1 #212)

Cosmic Boy was formidable even without his powers. During a Braalian holiday that prohibited him from using his powers, he single-handedly rescued his comrades from a trap (though he was gravely wounded). He was saved by the Emerald Empress, who was impressed by his sense of honor. (#215)

Cosmic Boy and Night Girl took a holiday to Braal that was interrupted by the Worldsmith, a powerful alien who remodeled planets for his clients. (Superboy & the Legion #236)

At some point, Rokk's family also relocated to Earth. (Adventure #335) Their neighborhood was the target of a terrorist "fireball" — a nuclear attack. (Legion vol. 2 #296) The Legion helped him rescue the family but Rokk's mother died. His father and brother sustained horrible burns and Cosmic Boy barely managed to restrain himself from killing the perpetrators. (#297)

When Garth and Imra decided to hang up their Lightning Lad and Saturn Girl uniforms to raise their newborn son, Rokk also agreed that it was time to step aside. (Legion vol. 3 #12), leaving his younger brother Pol, aka Magnetic Kid, his heir apparent. (#14) Even in retirement, he could hardly stay away from the Legion; he co-founded with Lydda and several others, the second incarnation of the Legion of Substitute Heroes.

Glorith Reality (Legion vol. 4)

Even in retirement, he could hardly stay away from the Legion; he was the one who opened up the doubts as to Superboy's authenticity, and he founded, together with Lydda and several others, the second incarnation of the Legion of Substitute Heroes. He eventually returned to Braal.

But although he was a hero, Braal was still a harsh world, and, when his planet went to war with Imsk, he was conscripted into its army, making sure to marry Lydda while he still could. He underwent the most shattering experience of his life, the massacre at Venado Bay. The Imskians had established a beachhead there, and, under the command of Salu Digby, the former Shrinking Violet, they set up a weapon called the damper - an object that would disrupt a Braalian's unique magnetic field. When the damper went off, Rokk lost his powers and his consciousness, and many Braalians lost their limbs or lives. When Rokk came to, he stumbled upon the Imskian camp, thinking that it was his own, and, when he heard of the presence of Imskians, slashed away with his laser-knife to get free. It's uncertain if he's even aware that it was he who slashed Shrinking Violet's eye...a scar she still wears to remember the atrocity in which she had been involved.

Still, it wasn't his magnetic powers which had made him so valuable to the Legion. It was his strong personality and leadership ability. That's why, when Reep Daggle set out to re-form the Legion, Rokk was the first person he contacted, and, when the re-formation became official, Rokk was the co-leader. He has since also become a father, Lydda giving birth to a son, who Rokk named after his late brother Pol.To help in a battle against Glorith, Brainiac 5 found a way to mechanically augment what remained of Rokk's magnetic powers, and it appears that the effect holds even without the machine's presence. This is quite useful to the Legion, which has been framed on criminal charges and is now on the run, but it appears to have made Rokk, now using the code-name Polestar to hide his identity, more aggressive and violent. This mania caused him to think that he was somehow able and obligated to re-assemble the Earth, and he seems oblivious to the damage he was actually causing to it. He was stopped when the young Legionnaires discovered that the gauntlets were causing the problem and Alchemist used his power to disintegrate them.

Rokk is the Time Trapper?

Rokk Krinn portrait from Who's Who #1 (1990); art by Keith Giffen and Al Gordon.
From DC Master cards: Polestar, card #18 (1994); art by Nelson.
Rokk finds himself in the librarty of the Time Trapper. From Legionnaires #18 (1994); art by Chris Gardner and Dennis Cramer.
Rokk learns that the Time Trapper is: himself! From Zero Hour #3 (Sept. 1994); art by Dan Jurgens and Jerry Ordway.

At the funeral for Laurel Gand, Rokk was kidnaped by Mordru and Glorith. They held him hostage in Glorith's keep—the Infinite Library of time. There he was trapped, so he began to read from the library. While consuming the annals of time, Rokk learned of the 30th century's ultimate fate—the Zero Hour. He remained for untold years, growing older then younger again. The infinite knowledge drove him mad with the drive to prevent the Legion's demise by any means necessary. To this end, he invented a new guise for himself: the Time Trapper.

Cosmic Boy II: Batch SW6

As the Trapper, his first act was to create an "Iron Curtain" in time to try to prohibit the Legion from all time travel. His grandst attempt was to divide the Legion into two chronal duplicates. The new set of Legionnaires was stored in "time stasis" beneath the Time Institute, where they were eventually unearthed by the Dominators and became the "SW6 Legion." He didn't realize that his actions were actually further weakening the time stream. He continued by creating an entire Pocket Universe in the 20th century. This universe was intended to be a safe haven for the Legion when the Crisis in Time occurred. This universe was destroyed by other fluctuations in time, and Rokk despaired, going even more mad. He was also weakened and further attempts to help the Legion were ineffective, especially in the presence of Glorith's great power. Eventually, the Trapper was attacked at the end of time by Monarch (Zero Hour #4) and he fell backwards in time. This created another paradox, as he fell to a time where Rokk had just entered the Infinite Library. In essence, he enlisted the help of... himself!

At the time when Polestar had just been banished to the Library, the Trapper told his story and convinced Rokk that the only solution to the crisis was to reunify the existing Legionnaires with their SW6 counterparts. (Valor #23) When the Legions began witnessing the time damage first-hand, they agreed to sacrifice their own existence to this plan, for the promise that the Legion would live again, restored and at full power. One by one, each Legionnaire touched their counterpart and disappeared. Once all pairs had merged, this time line ceased to exist. (Legion vol. 4 #61)

The Cosmic Boy of Batch SW6 had the same magnetic powers and superb leadership abilities. He was named to lead the New Earth team of Legionnaires just as he had the original team. He was badly injured by a stray bolt from Live Wire, and was still recuperating, leaving vice-chairperson Computo in charge. The SW6 Cosmic Boy was one of few Legionnaires to notice when the "crisis in time" took hold. He, Saturn Girl and Live Wire traveled into the past to investigate their origins and wound up fighting alongside the 20th century's heroes during that "Zero Hour." They returned to the 30th century believing they had stopped the menace, but soon learned that they must remerge with their older counterparts in order to repair the time stream. In true heroic fashion, Rokk joined hands with his older counterpart, and his best friends (both versions) and bid their reality farewell.


In his revsied original costume (more akin to the Earth-247 version), from Legion: Secret Origin #5 (2012); art by Chris Batista and Marc Deering.

In the Legion Retroboot, the history of the original Legion was more-or-less restored — inus the events of Legion vol. 4. This meant that Rokk and Lydda had never married and had a child.


A character called Cosmic Man appeared a year after Cosmic Boy, in Action Comics #258 (Nov. 1959). He was a rival hero to Superman, but turned out to be merely a robot.

Jim Shooter on Cosmic Boy: "Kind of a yutz—manly, strong, secure, and yet no one suspects that he isn't bright enough not to be. Questions of a philosophical nature rarely form in his mind. He is a good counterpart to Bouncing Boy, having that dumb ego B.B. lacks. He will shave around his ears forever. On the good side, he is dedicated, direct, and reasonable, he knows his lack of high intellect and delegates the thinking, rather than attempt it himself. He is a good leader, a quick thinker if not a deep thinker, and one who relates well to those behind him. Even as a leader he is a team player." —Interlac (1976)

Tom & Mary Bierbaum on Cosmic Boy: "Literally the 'rock' of the Legion, the foundation, the corner stone. Quietly, unobtrusively personifies Legion heroism. Not really a natural leader, tends to let others take the initiative. Never acted on his love for Imra and let Lydda choose him." —Interlac (2000)


Cosmic Boy has the native ability of all Braalians to manipulate the forces of magnetism.

Appearances + References


  • Action Comics #267, 276, 285, 287, 298, 319, 386, 389, 392
  • Adventure Comics #247, 267, 282, 290, 293
  • All-New Collectors' Edition #C-55 (1978)
  • Crisis on Infinite Earths #3, 5, 10
  • DC Comics Presents #2, 43
  • DC Super-Stars #17
  • Karate Kid #10, 12, 13
  • Legends #1, 2
  • Secret Origins vol. 2 #46
  • Superboy vol. 1 #100, 125, 147, 173, 176, 191
  • Superman vol. 1 #152, 156, 157, 172
  • Superman vol. 2 #8
  • Superman's Pal Jimmy Olsen #72, 85, 100
  • World's Finest Comics #284

Glorith Reality

  • Adventures of Superman #478
  • Valor #23
  • Zero Hour #3–1


  • Action Comics #859, 861-863
  • Action Comics vol. 2 #5-6
  • Adventure Comics vol. 3 #2 [505], 8 [511], 9 [512], 11 [514]


  • Adventure Comics #300–380 (1962–69)
  • Action Comics, #378–392 (1969–70)
  • Superboy (and the Legion) #197–258 (1974–79); becomes ...
    • Legion of Super-Heroes vol. 2, #259–313 (1980–84); becomes …
    • Tales of the Legion of Super-Heroes, #314–354 (1984–87)
  • Secrets of the Legion of Super-Heroes, 3-issue limited series (1981)
  • Legionnaires Three, 4-issue limited series (1986)
  • Cosmic Boy, 4-issue limited series (1986)
  • Legion of Super-Heroes vol. 4 #1–61 (1989–94)
  • Legionnaires #1–18 (1993–94)


  • Final Crisis: Legion of Three Worlds, 5-issue limited series (2008-09)
  • Legion of Super-Heroes vol. 6, 16 issues (2010–11)
  • Legion: Secret Origin, 6-issue limited series (2011–12)
  • Legion of Super-Heroes vol. 7, 23 issues (2011–13)

Rokk Krinn of Braal

Hu (father), Ewa (mother), Pol (brother)

Legion of Super-Heroes

Legion of Super Heroes vol. 4 #0 (Oct. 1994)

Reboot: Cosmic Boy III

Rokk Krinn (aka "Cosmic Boy") is a famous magnoball player. From Legion of Super-Heroes vol. 4 #0 (Oct. 1994); art by Stuart Immonen and Ron Boyd.
Leadership takes its toll. From Legion of Super-Heroes vol. 4 #72 (1995); art by Lee Moder.

The planet Braal had few things to be happy about before the creation of the United Planets. Its economy was perpetually mired in depression and it was involved in a ruinous war with the planet Titan. The one bright light in Braal's situation was the extremely popular sport of magno-ball, which, despite the fact that only Braalians could play it, was a showcase of the Cosmic Games.

The embodiment of this spark of optimism is Rokk Krinn, the magno-ball champion so dominant, he was nicknamed "Cosmic Boy." After his success in the games, he was set to on a tour of the newly-formed United Planets, of which both Braal and its enemy Titan were members, but his tour ended on its first stop, Earth, where he, Titanian Imra Ardeen, and Winathian Garth Ranzz stopped the attempted murder of Stargate tycoon R. J. Brande. Brande contacted him (and the other two) and brought them together to form the Legion of Super-Heroes. In the process, Brande did him the favor of bringing his manager Cuspin within range of Imra, who discovered his embezzling of Rokk's earnings. (Legion vol. 4 #0)

The three youths accepted Brande's offer to personify to United Planets as teenaged goodwill ambassadors, and Rokk was chosen leader of the team twice... once by the team's consensus, and once by Leviathan—the U.P.-appointed leader—who, after the death of Kid Quantum ceded the leadership. (Legion vol. 4 #62)

Shortly after the Legion's fight against the Composite Man, Rokk encountered Doctor Micah Aven of Titan, who expressed a suspicion that U. P. President Chu was manipulating the Legion for her own purposes and had done similar things before... including the engineering of the original Braal-Titan war. After the President began exercising more control over the Legion following the death of Apparition in battle against the White Triangle, Rokk, suspicious of her motives, had Invisible Kid form a squad to spy on her and Live Wire contact some other heroes to form a rescue squad in case they'd need outside help. (Legionnaires #36)

His forethought paid off in the end, when the president had the Fatal Five attack the Legion, and the two squads managed to save the Legion and reveal her treachery. However, feeling that the Legion might have outgrown him, Cosmic Boy has resigned his leadership, preferring to have an open vote for the position rather than keep it out of inertia from a time during which the rules and requirements were different. In the vote, he lost the post to Shrinking Violet, who had won it through the machinations of the Emerald Eye of Ekron. (Legionnaires #38) Ironically, Cosmic Boy was one of a group of Legionniares were were flung by the Eye back to the twentieth century when Violet went berserk. (Legion vol. 4 #84)

While in the twentieth century, he grew extremely close with Saturn Girl. In order to protect her from Doctor Psycho, he linked his mind with hers and fell into a coma from Psycho's attack. When he awoke, he found that he'd become engaged to Saturn Girl. (Legion vol. 4 #94) This oddity was sorted out on their wedding day, it was discovered that Saturn Girl, feeling a need for structure in her life, had unconsciously animated his body and that their entire romance was a fiction of her mind. (#96) Following this revealation, the Legion managed to cure him for real, whereupon he graciously took the news that Saturn Girl had always been in love with Live Wire. He redoubled his efforts to get the team back to the thirtieth century. Following their return, he has ceded leadership of the reunited team to Invisible Kid. (#100)

Cosmic Boy was instrumental during another tragic phase in the Legion's history. He and a team were stranded deep in space when the alien Blight struck Earth. (Legionnaires #78) After a month's journey, they arrived to find the Legion enslaved. (Legion vol. 4 #122) But just after the Blight were neutralized, another group of Legionnaires was shunted outside of normal space/time. (#125) In the aftermath, the Legion disbanded and evil forces took over Earth. Cosmic Boy kept a covert team together to try to combat this evil. They once returned to his homeworld, Braal, for a ship to help make the journey back to Earth. (Legion Worlds #3)

Cos's espionage squad was on-hand when the lost Legionnaires returned, and helped restore the Legion to greatness. (The Legion #2) Since its reforming, he has been happy to let others fill the leadership role. In fact, he has become romantic with the Legion's next leader, Kid Quantum. (#10, 26)


Olivier Coipel on Cosmic Boy: "Cosmic Boy is quite a square and not one of my current favorites because I have yet to find something fun in him: I know I wouldn't get along with him in real life!" —Comic Book Resources


Cosmic Boy has the native ability of all Braalians to manipulate the forces of magnetism.

Appearances + References


  • Final Night #1, 4
  • Green Lantern vol. 3 #81
  • Impulse #21
  • Showcase '96 #10-12
  • Superboy vol. 3 #21
  • Superman Plus #1
  • Superman vol. 2 #119
  • Teen Titans vol. 3 #16
  • Teen Titans/Legion Special #1


  • Legionnaires, 81 issues (1993–2000)
  • Legion of Super-Heroes vol. 4, #0, 62–125 (1994–2000)
  • Legion: Lost, 12-issue maxi-series (2000–01)
  • Teen Titans/Legion: Universe Ablaze, 4-issue limited series (2000)
  • Legion Worlds, 6-issue limited series (2001)
  • The Legion, 38 issues (2001–2004)
  • Final Crisis: Legion of Three Worlds, 5-issue limited series (2008-09)


cosmic boy

Rokk Krinn of Braal

Unnamed parents, Pol Krinn (brother)

Legion of Super-Heroes

Teen Titans/Legion Special (2004)

Threeboot: Cosmic Boy IV

Cosmic Boy plots to keep control of his team with his most loyal Legionnaire, Triplicate Girl. From Legion of Super-Heroes vol. 5 #3 (2005); art by Barry Kitson.
Cosmic Boy is recruited by the Knights Tempus of the 41st century. From Supergirl and the Legion of Super-Heroes #30 (July 2007); art by Barry Kitson and Mick Gray.

Rokk Krinn was one of the founders of the Legion of Super-Heroes. He hails from Braal, where everyone has the ability to weild magnetic forces. His level head and charisma made him the ideal person to lead the team in its earliest days.

But as the team grew, Cosmic Boy discovered new challenges to his leadership, primarily in the form of fellow Legionnaire, Brainiac 5. As the Legion began facing the growing menace of Terror Firma and their leader, Lemnos, Cos became paranoid about Brainy's covert plots. For good reason, too; Brainiac 5 was constantly undermining Cosmic Boy's authority.

Cos ultimately sanctioned stealth actions to uncover Brainy's plans. His aim was to unify the team under one purpose, but he achieved quite the opposite. When Brainiac 5 learned that his lab had been infiltrated, (#7) the Legionnaires took sides. Before tensions could escalate, Rokk learned that his home world was going to be sealing off its borders. He decided to leave the team, but changed his mind en route when he saw that the Legion still needed his leadership. (#8) In the end, Brainy and Cos took down down Lemnos together. (#13)

After the battle with Lemnos, the Legion was indeed more unified. But Brainiac as continued to do his own thing, Cos had new problems to solve—like the unexpected arrival of Supergirl from the 21st century. (#16) Cosmic Boy and the other founders, Saturn Girl and Lightning Lad, made Supergirl an honorary Legionnaire (#17)

Per the Legion's bylaws, a new leadership election was held, and Cosmic Boy opened the voting to all Legionnaires at-large—thousands of underagers across the galaxy. (#21) Ironically, Supergirl won this election and Cos and Brainy got significant votes as well. (#31)

His last mission as leader marked a significant turning point for Cosmic Boy. The entire United Planets came under seige from the Dominators. To defeat them, Cos was forced to make the very difficult decision to order Mon-El back into the Phantom Zone—and take the Dominion with him. The public believed that Cosmic Boy had ordered the Dominion's destruction, but he could not reveal the truth to exonerate himiself. Mon-El was believed to have died, but his return to the Zone actually kept him from succumbing to lead poisoning. (#27-30)

Before Cosmic Boy could face the public, he disappeared. Privately, he received a visit from three youths from the 41st century—the Knights Tempus. These three teens claimed Cosmic Boy's legacy of heroism had inspired their own team. They invited him to join them in the future. Cos has not returned since. (#30)

In his absence, Brainiac 5 cleared Cosmic Boy of the charges for the destruction of the Dominion—by incriminating Mekt Ranzz for the crime. Apparently, it was Mekt's idea to destroy the Dominion, and his Wanderers had telepathically planted the suggestion in Cosmic Boy's head. (#33) This was one of three missions orchestrated by Brainy with the pretext of finding Cosmic Boy. (#31-36)


Cosmic Boy has the native ability of all Braalians to manipulate the forces of magnetism.

Appearances + References


  • The Brave and the Bold vol. 3 #4-5
  • Teen Titans/Legion Special #1


  • Legion of Super-Heroes vol. 5, 50 issues (2005–09)


Rokk Krinn of Braal

Unnamed "prime father"

Legion of Super-Heroes

Superman vol. 5 #14 (Oct. 2019)

Rebirth: Cosmic Boy V

On Braal, Rokk Krinn battles metallic beasts for sport. From Legion of Super-Heroes vol. 8 #4 (Apr. 2020); art by Mike Janin.

On the planet Braal, one percent of the population have the power to control magnetic forces. Rokk Krinn was one of these; he used his ability for sport and became a champion in that world's contests to battle great metallic beasts. Rokk hoped to go to the Intergalactic Olympics, but authorities on Braal nominated him to participate in a program promoting United Planets youth. His "Prime Father" (who was also his coach) encouraged Rokk to travel to Daxam to meet President R.J. Brande.

En route, he met Garth Ranzz and Imra Ardeen. Brande called the three together for their power, counsel and perspective amid growing discontent in the U.P. When Brande was attacked by the alien Horraz, Rokk and the others leapt to her defense. (Legion vol. 8 #4)

As Cosmic Boy, Rokk was a founding member — and the team's first leader — of the Legion of Super-Heroes.

Cosmic Boy is dating Shadow Lass. (#3)


Cosmic Boy manipulates magnetism.

Appearances + References


  • Legion of Super-Heroes: Millennium #2
  • Supergirl vol. 7 #33
  • Superman vol. 5 #14-15


  • Legion of Super-Heroes vol. 8, 12 issues (2019–2021)


Other Versions

Cosmic Boy with the Legion. From "Cry Wolf," Legion of Super-Heroes season 2, episode 3.


Cosmic Boy was a member of TV's Legion of Super-Heroes cartoon. Even though he was a founding animated member, he does not appear in the cartoon frequently.


Rokk Krinn (played by Ryan Kennedy) appeared twice on television's Smallville: along with Imra and Garth in season 8, episode 11 (2009); and later that season, in episode 22.