H.R.Giger & Dr.Stuart Sumida

Alien, known as one of the best horror sci-fi film of all time and the design of the alien was absolutely incredible (a good mixture of the raw power of the alien and sheer horror it can give it to the audience was fabulous). Necronom IV, Giger's previous painting and an inspiration towards to his creation of Alien, would be the starting point of my model's and the basic research.

H.R.Giger's Necronom IV paintings

Series of images of Aliens (surrealist print that formed the basis for the Alien's design)

 However, alien or extraterrestrial spices have different body structure so to educate myself, animal bone/body structure would be a great way to start. 

Dr Stuart Sumida, who well known for his knowledge of Palentology and Vertebrate Morphology and have extensive working experience in animation such as Lion King and Kung Fu Panda.

Row sketches of Lion King's Simba and Kung Fu Panda's Po