LogFAQs > #959554962

Oh, in all seriousness, the title is more a reference to her "fusing" with a Metroid. In the second game, she hunts Metroids to extinction with the exception of a newborn that imprints on her as its mother. This turns out to be a bad idea because the Chozo, the advanced bird alien race that created her suit and adopted her when Ridley killed her parents, specifically created the Metroids to prey on a species known as the X Parasite. The X Parasite is essentially a big blob of good that infects a lifeform, kills it, and copies its form and knowledge. Samus is attacked by one of these parasites and she's only saved by "fusing" her DNA with that of the last Metroid.