H. R. Giger
The "Xenomorph" design is credited to Swiss surrealist and artist H. R. Giger, originating in a lithograph titled "Necronom IV" and refined for the series's first film, "Alien". The practical effects for the Alien's head were designed and constructed by Italian special effects designer Carlo Rambaldi. The species's design and life cycle have been extensively augmented, sometimes inconsistently, throughout each film.