“Records indicate that Callum had a rough upbringing in the projects of Glasgow. He was a vandal, scammer and shoplifter, who survived the streets by living off unemployment checks, theft and the occasional odd job. Despite his situation, his cynical humor made him a leader among his friends. His education on the streets makes him handy in a fight.”
— Survival Guide
Callum is a playable co-op character in Far Cry 3. Serving as a possible leader of his group Callum is a petty criminal and chef born in Scotland, UK. It is unknown if he is the real leader of his group, but he seems to have taken the position.
Callum can also be identified as a fan of the Scottish football club Rangers. This is evidenced by the fact that when his 'football fan' costume is chosen, his T-shirt is an almost exact replica of Rangers' 2011–2012 home shirt, only missing the shirt manufacturer and shirt sponsor, and with a changed crest, similar to Frank Bilder's GAA jacket from Far Cry 2.
Growing up in the projects of Glasgow, Callum developed an early attachment to knives. At six, he won his first knife fight. At 12, he was already leading a street gang of his own. He spent part of his teenage years working as a chefs' apprentice in Wales, UK.
After years of dodging serious trouble, Callum's ruthless spirit finally took its toll. He picked a fight with the wrong man, snapped and incidentally beat him to a pulp. Hunted by police and gang members, he fled Britain and found a job on the SS Astrid.
Callum has a cynical, black-humoured point of view, but becomes aggressive, ruthless and, at times, psychotic when provoked.