in the AVP (Aliens vs Predator) computer game I believe the game mode was called 'life cycle' which is fairly apt here! You started as face hugger and had to find a victim to incubate. You came out of their corpse as chest burster and had to find something to eat so you would grow.
Born into world as peasant, rise up thru the ranks to become a bandit, knight, royalty, wizard, etc!