Schöner Clip von der Stan Winston School of Character Arts:
The chestburster reappears later in the film when Ripley and the military team finally locate the missing colonists of LV-426, who have all been cocooned for use as xenomorph incubators in the alien nest. One colonist, barely clinging to life, begs our heroes to kill her. Moments later, a chestburster explodes through her sternum and the commandos burn it with their flamethrowers.
To achieve the effect, Winston and his crew created two chestburster puppets. The first was built to be tough. as it needed to be able to rip through Coles' artificial foam latex chest multiple times. The second, "post-burst" puppet didn't have to withstand the same abuse and so it featured a more delicate cable-controlled mechanism that allowed a wide-range of fluid motion.