"He's one of the greatest soldiers ever to serve the Star Fleet, sir, a man of such bravery and resourcefulness that he alone was revived by the on-board computer to protect your life. My father, sir, is Arnold J. Rimmer."
-Michael McGruder (Last Human)
When Yvonne McGruder was hit on the head by a winch aboard Red Dwarf, she met Arnold Rimmer in the lift. The two of them enjoyed a brief love affair before each of them decided to wait for the other to call, Rimmer wanting to 'prove' that McGruder cared, while McGruder recovered from her concussion and believed that the relationship with Rimmer was a delusion based on her own pre-existing interest in him. When neither called, they went their separate ways without mentioning it again. Yvonne left Red Dwarf shortly after, never telling Rimmer that she was pregnant with his child. Red Dwarf was lost before Michael was born.
Michael was brought up by his mother, who decided to tell Michael who his father was but embellish the details of Rimmer's personality. She invented stories of Rimmer's great courage and resourcefulness, making Michael believe that his father was the greatest warrior in the Space Corps, fearless and indestructible.
Michael spent his youth trying to live up to Rimmer's exaggerated memory. He was inspired to become as great a soldier as he could be, with his mother working very hard to put him through college and West Point Academy. He graduated first in his class and entered the Space Corps Marines.
Michael served in the SCM with distinction. He fought in the Saturn War on Hyperion and was decorated for bravery. When Red Dwarf's black box splashed down in the Pacific, Michael learned that his father had been resurrected by the ship's computer to keep the sole survivor sane.
Later, Michael was serving as a personal bodyguard to Dr. Robert Sabinsky, President John Nixon's chief scientific advisor. When it was decided to send a terraforming mission to the Andromeda galaxy to create a new home for humanity, Michael volunteered to lead the GELFs, droids, simulants and symbi-morphs to tame the new world. He did this partially in hope of encountering his father one day.
Michael had his ageing gene removed, slowing his body clock, and was put into deep sleep aboard the Mayflower. During one of his routine checks of the vessel, he was tricked into releasing the passengers. After a bloody mutiny, the ship entered the Omnizone and crashed into a volcanic moon. A group of GELFs took Michael prisoner and fled in an escape pod.
Years later, Michael was offered the chance to colonise a world that the GELFs were terraforming in order to traverse the Omnizone. He and two thousand other prisoners landed on the planet, only to encounter The Rage, a gestalt made up of the negative mental energies of innocent people that tried to destroy all the settlers. After many of the settlers had killed each other under The Rage's influence, the survivors discovered that they could overcome The Rage by making the Circle of Sacer Facere. The settlers had to sit in a circle, whereupon The Rage would consume one of them but leave the others untouched.
When Lister and Reketrebn landed on Rageworld with a second group of prisoners, they encountered Michael and forty survivors. Michael was ecstatic at meeting someone who knew his father, bombarding Lister with questions about Rimmer's bravery and heroic exploits. Lister, in order to spare Michael's feelings, decided to continue Yvonne McGruder's deception and told Michael that his father was a magnificent warrior.
When Rimmer landed with the Starbug crew, Lister introduced him to Michael, who fainted clean away. Rimmer followed suit upon learning that he had a son. Lister encouraged Rimmer to come clean and tell Michael the truth about himself, but Michael took the news that his hero was a vending machine repair man very badly.
When Lister's evil doppelganger took Michael hostage, Rimmer failed to stop him despite it being a simple case of grabbing a nearby pistol. When Rimmer was locked up, he managed to escape and used an astro-stripper to overcome the doppelganger, finally winning Michael's respect. Rimmer's light bee was severely damaged in the process. Michael forced the doppelganger to join the Circle of Sacer Facere, which killed the doppelganger.
Rimmer volunteered to deliver the Oblivion Virus to the Rage, in order to allow the others to escape into the caves for the journey through the Omnizone. Michael joined the survivors to make a new life on the surface. He, Kryten, Cat and Reketrebn began to search for Rimmer's light bee in hopes of repairing him with the antidote virus.
Michael typified all the best elements of the Space Corps Marine.
He was extremely strict with his appearance and performed his duties in a professional fashion, as he expected his father would have been proud. His pride in his heroic father was paramount to Michael, forever making him compare himself to Rimmer and trying to emulate his heroism.
Rimmer insisted that all of Michael's excellent actions and strong personality came not from his father, but from Yvonne who raised a hero single-handed.
Michael was 6 foot 2 inches tall and very fit. He had short blond hair, broad shoulders and extremely chiselled features. He had his aging gene removed, so when he finally met his father they appeared to be roughly the same age. Despite being in his 40s, Michael looked no older than his late 20s.
It is unknown if Michael exists in any of the other dimensions where Rimmer had a similar relationship with Yvonne McGruder.
Dimension Jump XIX
For the opening ceremony of The Red Dwarf Official Fan Club's 19th Dimension Jump convention, a version of Michael McGruder appeared for the first ever time in a visual medium. In this sketch, McGruder was portrayed by Henry Imbert, interrupting proceedings with a message that the convention was under threat from a loose Polymorph.
Despite offering his help and that of the Gelf Interception Task Squad, a misunderstanding with the Fan Club team led to an offended McGruder withdrawing his offer of help and placing the event on quarantine.
By the end of the convention however, an intercepted transmission from the Mayflower showed that McGruder was in equal danger, with a sinister doppelganger appearing behind him before the signal was lost. The post event email sent out to attendees revealed that this was an encounter he did not survive, stating:
"The 'Welcome back Michael McGruder' reception is about to begin in the refectory. Michael says he'd like to invite everybody, especially those who weren't able to attend his funeral."
The parentage of this version of McGruder is not alluded to, but his appearance in the real world is explained through his crew having broken through dimensional barriers.