The word for today is…
homunculus (noun) – 1. A diminutive human.
2. A miniature, fully formed individual believed by adherents of the early biological theory of preformation to be present in the sperm cell.
Source : The Free Dictionary
Etymology : “Tiny human being produced artificially,” 1650s, from Latin homunculus (plural homunculi), literally “little person,” with -culus, diminutive suffix, + homo (genitive hominis), which technically meant “male human,” but it also was used with a sense “the human race, mankind;” while in Vulgar Latin it could be used as “one, anyone, they, people” and in logical and scholastic writing as “a human being, person.” This is conjectured to be perhaps from PIE ghomon-, literally “earthling,” from *dhghem- “earth”.