If your referring how the look in the actual film maybe dont use a production pic as your example of how it doesn't hold up. Ridely also purposely kept the details obscure and in the shadows, I would say more than Cameron till the final. So I dont understand the point your tying to make. The big chap alien also moves in a specific very deliberate and strange way, its just not like a rabid animal. Yeah he hired stuntmen and dancers and it shows all the aliens look way more stocky and less sleak except for a few scenes with a puppet that has radically different proportions than the suits. Too me the alien in the first looks way more like a living creature than the aliens drones. the queen though was done very well, which I suspect took a lot of the budget away from the drone costumes and it shows to me(also taking away the dome was a shit idea and lazy because Cameron had concerns of it breaking, fucking hate domeless aliens). Of all the first 4 films i think aliens had the worst costumes. Why would you say that a quadrupedal xeno is what is a xeno to you ?, its not presented as such in the first(except i assume it was in the ducts when it gets Dallas) and in the second they are a mix both. I just dont understand how you can even say that shitty pic is WHAT a xenomurph is to you, how do you ignore the original. The tail is a weapon the the flutes on the back could be anything from how it breaths to cooling it down to how it shits.