|Age||Less than one year|
|Cause of Death||Unknown|
|Family||Marcy (Mother, deceased), Patrick Ross (Father, deceased), Various Half-breed half brothers and sisters (deceased), Sara (Half sister, alive)|
Marcy's Son (also known as Lindsey's Son in the novel) is the only male alien/human hybrid seen born naturally from a human mother in Species II. He is the firstborn son of Patrick Ross, who was infected with alien DNA, and a woman known as the Debutante. He is followed by a half brother born to another woman known as the Debutante's sister the same night he was born.
Conceived shortly after Marcy/Lindsey had sex with Patrick, this hybrid was born in the bathroom of a hotel room, killing his mother in the process. He was later seen being taken by his father, along with his half brother, to a barn house where he developed over the next few weeks before entering the cocoon stage to be reborn as an adult. Prior to his rebirth, he was likely killed with infected human DNA because his immune system couldn't cope with human diseases, such as sickle cell anemia.
Marcy/Lindsey is the biological mother of her half-alien son. However, he doesn't really have a relationship with her. After being impregnated by Patrick, she immediately gives birth to him in the bathroom and dies shortly after.
Patrick Ross is the biological father of Marcy/Lindsey's Son. Shortly after he and his half brother are born, Patrick hides their mothers' corpses and them in a remote shed on family property to cocoon, awaiting their rebirth as adults.
- He is the firstborn child of Patrick Ross and the first hybrid to be created naturally outside a science lab.
- His birth demonstrated that being born to a human mother is fatal for the mother.
- He is a second-generation hybrid.
- He is Marcy/Lindsey's only child.