Name: Cosmic Boy
Universe: Post-Crisis
Alter Ego: Rokk Krinn
Occupation: Legionnaire
Marital Status: Married
Group Affiliation: Legion of Super-Heroes
Base of Operations: The 30th Century
Known Relatives: Hu Krin (father), Ewa Krinn (mother, deceased), Pol (brother, deceased), Lydda Jath Krinn (wife)
Height: 6 ft.
Weight: 190 lbs.
Hair Color: Black
Eye Color: Blue
First Appearance: Legends #1

History:
Rokk Krinn's parents were natives of the planet Braal, a 30th century former Earth colony. The people of the planet Braal, long menaced by metallic beasts that roamed the countryside, evolved the power to project magnetic waves through their hands to protect themselves from these beasts. Rokk himself was born on Earth, where his parents were employed as migrant workers. Shortly after Rokk's birth, the Krinns returned to Braal, where Rokk exhibited an uncanny magnetic prowess, later becoming the youngest-ever champion of the Braalian sport of magno-ball.

Eventually, however, severely depressed economic conditions on Braal forced Rokk Krinn to emigrate to Earth when he reached fourteen, the age of Braalian adulthood. En route to Earth, Rokk met teenager Garth Ranzz, who was traveling to Earth from his home planet of Winath. Ranzz could project lightning through his hands. The boys became friends, and both developed an adolescent crush on another young passenger, a telepath from the Saturnian moon Titan named Imra Ardeen.

As their ship arrived in Metropolis, Imra's telepathic powers warned her that assassins were about to gun down R.J. Brande, another passenger and one of the galaxy's wealthiest men. She called out a warning and the two boys, spotting the assassins, used their super-powers to apprehend the gunmen and save Brande's life.

Brande was highly impressed with the three youngsters. A longtime admirer of the legendary 20th century teen-age hero Lar Gand, also known as Valor, Brande suggested that Rokk, Garth, and Imra use their own paranormal abilities in the cause of justice. He offered to equip them and fund their efforts if they were willing to band together as a team to do good works across the galaxy. The three agreed and, under Brande's guidance, formed the Legion of Super-Heroes.

The teen-agers chose code-names under which to operate. Krinn, or "Cosmic Boy", was chosen by the Legion's computer as the ideal leader for the team; under his leadership, he built up the Legion's membership and established the team's constitution and style of operation.

Cosmic Boy enjoyed numerous adventures with the Legion and participated in many of their most challenging cases. During his Legion days, his parents moved back to Earth to be closer to him. Unfortunately, Rokk's mother was killed by fireball terrorists. The injustice of this tragedy led his brother Pol to enter the Legion Academy – and later the Legion – as Magnetic Kid. It also prompted Rokk's decision to join his friends Imra and Garth in retiring from active duty in the Legion. Rokk did not sever all ties with his former teammates; he acted as a Special Advisor to the team and co-founded the second Legion of Substitute Heroes.

Tragedy struck the Krinn family once more at the end of the great Magic War, when Magnetic Kid gallantly gave his life to save the galaxy. After the Legion disbanded in the year 2989, Rokk married Lydda Jath, the substitute Legionnaire called "Night Girl". The couple moved to Braal on the eve of its greatest economic depression, and when the Braalian government declared war on the planet Imsk, Rokk was drafted into the Braalian military. His magnetic powers were permanently destroyed in the battle known as Venado Bay. Nevertheless, after returning to Braal, Rokk was the first former Legionnaire contacted by his old friend and comrade Reep Daggle, who asked Rokk to help him establish a new Legion of Super-Heroes. Rokk agreed, making him the only founding member of both teams.

Powers:
Rokk Krinn no longer has the natural Braalian ability to control magnetism; nonetheless, his years as a Legionnaire instilled in him great athletic prowess that has not diminished with age. In particular, he is well-versed in Kujui, a martial art of Braalian origin.