Malcolm appears in The Sims 3 as the only child of Geoffrey and Nancy Landgraab. He would presumably be an elder, or close to becoming one, by the time of The Sims 2, but he does not appear in The Sims or The Sims 2.
He lives with his parents in a large house in Sunset Valley. He is different from his parents, as he is a good, ambitious bookworm. However, he is more like his father, a family oriented doctor, than his mother, who is a snobby businesswoman. According to his mother's bio, she often neglects Malcolm because she is overly concerned with her looks, job, and social life.
In his relationship panel, Malcolm starts off with a higher relationship with his father than with his mother. Also, if his father gets promoted, he will likely get a lifetime wish to become a surgeon, but he doesn't get any related wishes if his mother gets promoted. This suggests that he aspires to be more like his father than his mother.
Although his parents are rivals with the Altos, he seems to have no current conflict with their daughter, Holly Alto.
It has been reported that, when he grows to adulthood, he does not resemble the Malcolm Landgraabs in the console versions of The Sims 3.[confirmation needed]
A character named Malcolm Landgraab, whose family founded the town of Beacon Bay, appears in The Sims 3 for Nintendo DS, married to self-professed gold digger Bambi Landgraab. He is a gene therapist, meaning that, if they are the same person, Malcolm followed his father into medicine instead of his mother into business. Like Alex Goth's presence in the game and Holly Alto's turn toward evil, this is assumed to be an on-purpose paradox.
Malcolm is the son of Nancy Landgraab who, like most other Landgraabs, expects her son to inherit her family's dynasty. (His father, Geoffrey took the Landgraab name when he married Nancy.) However, he looks unhappy about the thought and obviously isn't happy about the family rivalry. The connection between this branch of the family and the one in The Sims 2: Open for Business is unspecified, but it is likely that he and Malcolm Landgraab III are contemporaries. He may be the great-nephew of Malcolm Landgraab I, the second cousin of Malcolm Landgraab II, the cousin of Malcolm Landgraab III and the second cousin of Malcolm Landgraab IV, but that is not certain. It is also possible that he is a young version of the Malcolm Landgraab in The Sims: Bustin' Out and/or The Sims (console), and therefore the father of Mimi and Dudley Landgraab, but that is speculative.