Marab was a male Klingon warrior for the Klingon Imperial Fleet in the 22nd century. He was the son of General K'Vagh, but at his own request he received no special treatment from his father throughout his career.
That year, Marab and his unit boarded Enterprise NX-01, from an attacking Klingon warship, with the intention of crippling the Earth ship by altering its engineering subroutines. Although the mission was successful – the ship was slowed down and thus was unable to interfere in the Klingon attempts to genetically engineer the augment virus – Marab was wounded by a MACO and subsequently captured while his boarding party attempted to escape.
After the Enterprise crew learned that Marab was a Klingon despite his Human appearance, Marab was placed in the brig, next to a holding cell containing the ship's armory officer, Lieutenant Malcolm Reed, who had been imprisoned for betraying Captain Archer's trust. Reed attempted to assure Marab that they were both looking for a way to cure the Augment virus, but Marab refused to listen to a mere Human. Eventually, Marab was convinced to provide Archer and crew with the location of the colony where the viral research was taking place; he was subsequently released from the ship's brig and returned to the custody of General K'Vagh.
However, the reunion was soon in jeopardy, as Marab and the other members of his unit continued to grow weaker from the effects of the virus. After a cure was developed, Marab and his soldiers were once again healthy, although they retained their Human appearance. (ENT: "Affliction", "Divergence")