Decided to go with a more slim design for the back. I thought to myself "Would it be able to crawl through an air vent to catch a victim?". The long back tubes screamed "No" for me, so I looked at an early Giger design and tried a compromise between the two.The goal is that the alien can rotate its head 90* upward and it would fit between the "shoulder blades" without adding too much volume to the silhouette.
Before ---> After
Before ---> After
I'm also reworking the rib cage to be more flowing interlocked
Before ---> After
ZBrush