Garth was born to Stephanie and Chuck McKrimmon on a small world on the fringe. His parents and almost all of the local inhabitants worked on a large farm complex with over half a million head of cattle and fields that covered over a tenth of the planets surface. The while area was run by the Ni Wong family headed by Kim Ni Wong, the Ni Wongs were from the core worlds and had set the farm up to finance their political careers in the more civilized regions.
Garth early life was quite happy although his family was never very wealthy but his father earned enough to provide for Garth, his mother and his three younger sisters (Eve 2 years younger than him, Jesabell 4 years younger and Lilith 8 years younger). This all changed shortly before Garth's eighth birthday when his father was killed in a stampede. Garth was forced to leave school and start work on the farm in order to provide for his mother and siblings. He had to grow up quickly and often had to use his fists to protect his family, perhaps more frequently than he should have.
Garth quickly showed an instinctive understanding of both animals and farm machinery. He picked up some training on farm equipment maintenance from Joe Peck, the previous head mechanic on the farm, and by the time he was 25 Joe had retired and Garth had taken his place. However, Garth had his eye on greater things, Clara Ni Wong, Kim's youngest daughter. If he married into the family he would be made for life and the girl seemed to be sweet on him.
However, not all was happy in the 'Verse. Many were unhappy that they toiled all day on the farm to provide wealth for a core world family, and tensions were building. The situation finally reached boiling point with the outbreak of the war, when a full scale riot broke out between many of the farm hands and the Ni Wong family and the workers loyal to them. In the fighting Garth's mother was killed by a mob and his sisters fled. Garth protected Clara and the rest of the Ni Wong family from their former employees and eventually got them off planet and back into the hands of the Alliance.
Following this Garth joined the Alliance military and worked as part of a tank crew along side Helen 'Faster' Fraser (driver), Yon 'Boom Boom' Fat (gunner) and Richard 'My way' Briggs (commander). He was highly sought after due to his mechanical skills but saw relatively little actual combat. His biggest role in the war was on the propaganda front, a film crew heard of his exploits in helping the Ni Wongs escape and decided to use him in an interview to show to the fringe worlders what they could join the alliance. The film was also edited by the crew to play up the core world assumption than all fringe worlders were stupid and uncouth. This film was widely shown in both the core and fringe worlds leading to Garth widely being hailed as a traitor by the Indies.
Following the end of the war the Alliance military was cut back and Garth and much of his unit was disbanded. Garth returned to his home hoping to return to his old job and life, however, he found much had changed. Many of the old jobs, including his own, had been given to new core worlder staff, and worse, the man that took his role, Charles Burgh, was engaged to Clara. Enraged, Garth confronted Clara and she revealed that she had never felt anything for him and just enjoyed teasing him. Furious, Garth used his skills to sabotage much of the farm machinery, leading to the Ni Wong mansion burning down, and fled into space.
Garth spent a few years wandering space lanes doing whatever odd jobs he could get, and sometimes acting as a leg breaker for local kingpins. However, his reputation prevented him from settling down anywhere for long. It was during one of his 'collection' jobs that he first met up with Daniel - he was hired to 'encourage' Daniel to repay a loan to a local underworld figure, Jimmy 'no nose' Darby. However, Jimmy decided to betray Garth, and tried to kill both him and Daniel to collect a bounty on Garth's head and to serve as a warning to others who owed him money. Daniel and Garth teamed up to escape the ambush set up for them and fled in Daniel's ship. Shortly after this Daniel purchased the Wink and a Smile and hired Garth to help refurnish it and eventually to crew it.
Garth is generally quite anti-social and is a man of few words, he tries to keep himself to himself. He can be quite quick witted but his general demeanour tends to make him appear stupid which can lead to others underestimating him. He has a short fuse and even fairly minor insults can set him off although he has more tolerance for the few individuals he considers friends, particularly touchy subjects for him are his lack of education and his position as a 'traitor'. He can be quite chivalrous on occasions when protecting women particularly those younger than him although this will not stop him protecting himself if attacked by a woman. He is quick to use his fists to solve any problem but is slow to use a gun or kill anyone, he prefers to let someone know that hes beaten them rather than kill them, a factor that he earned him several enemies. He shows a softer side when it comes to dealing with animals. Despite his technical brilliance he is something of a Luddite at heart, instinctively distrusting newer pieces of technology for older more reliable mechanisms.
Garth has a face that only a mother could love, and his mother is dead. No one feature is particularly bad but put together they all clash. His nose broken one too many times is spread across his face, his skin is sandblasted and aged by a life spent working outside under a hot sun, his ginger hair is patchy from the onset of baldness, and his pale green eyes are slightly crossed. He tends to wear tough-wearing, practical clothes, such as jeans and leather coats. He prefers to wear hats with wide brims which shade his face. When 'working', he will wear plate armour, or better if he can get his hands on it.
- Daniel Gabe: Garth sees Daniel more as an equal than an employer, he somewhat looks down on him for his dandyish ways but recognizes that hes very good at getting people to do what he wants. He is quite jealous of Daniel's success with women but doesn't want to say anything of it.
- Lizbeth Hasegawa: Garth tends to see Lizbeth as a younger sister and can be quite protective of her and her 'honour'. He has something of a good natured rivalry with her about their mechanical skills, he is trying to get her to recognize the superiority of older equipment over newer technology.