The Pyramid - The name of the structure where nearly everything goes down. It was originally designed to look more pyramid-like, but became more dome-like in reference to some of H.R. Giger's Alien designs for "egg-shaped mounds." The book contains one of the earlier, unused pieces of concept-art from when it was still a pyramid, which reveals an entirely different and more civilized vision for the landscape of LV-223.
The Engineers - Everyone already knows them as the aliens who created everything, but it's worth noting this name comes from Spaihts' original script for the film. Their physical design, particularly their head, was, "inspired by Michelangelo's David, Elvis Presley and the the Statue of Liberty." The mandate for their exosuit was, "Russian cosmonaut meets Samurai."
The Ampule Chamber - AKA the Room With the Giant Head. Scott's cue to the design team was to treat it like a cathedral, though without any clear ties to known religions. The murals on the ceiling depict the "Creation, Armageddon, and Judgment cycle."
The Ampule - These are the containers found within the ceremonial chamber. 70 ceramic Ampules with lids were crafted and carved with alien text by hand. Note: what oozes out of the Ampules after they're activated is referred to as the "black slime."
Babyhead - The production nickname for what Fifield turns into after being infected by the black slime. The original designs had him transforming into something remarkably more alien, as partially seen below.
Hammerpede - A production nickname for the snake-like creature that evolves from the black slime inside the Ampules. Its design was inspired by translucent sea creatures and it was built practically to be used on set. In fact, when it breaks Millburn's arm, Ridley Scott was operating the cables inside it.
The Juggernaut - The production name for the Engineer's spaceship. The design had to be modified from the crashed ship seen in Alien because the team modeled it and found out that its original horseshoe shape meant that it wouldn't roll like the film required it to, so its ends were brought in a bit to give it more of a donut shape.
The Orrery - The holographic navigation system David activates inside the Juggernaut's hibernation chamber.
Trilobite - The team's name for the impregnated creature Shaw removes via Med Pod-assisted cesarean. Animatronic versions of both its embryonic and grown forms were created for the film, with its final look being created by famed conceptual designer Neville Page.
The Deacon - Ridley Scott's own name for the offspring of the Trilobite and the Engineer, who dubbed it so because the final design - which includes elements from Shaw, the Engineer and the Trilobite - looked, "like a Bishop's mitre, the evil Deacon's pointed hat." Two versions of it were built: One for inside the birthing sac within the Engineer, and one for when it stands up.