By now it is pretty clear that Project Hail Mary’s Rocky has won everyone over. The faceless, five-limbed engineer from the 40 Eridani system has become one of the most beloved characters in recent science fiction film, and an incredible amount of detail went into bringing him to life. Most of that detail lives beneath the surface, which is exactly what makes it worth digging into.
Tom Blake, a designer and 3D artist who worked on Rocky's creature and prop detailing for the film, recently shared a four-image carousel on Instagram functioning as an official guide to the markings carved across Rocky's limbs with their placement, their meaning and the thinking behind them.
Rocky’s amazing details
As Blake wrote in the caption: "I made this guide so everyone knew exactly what Rocky's markings looked like, what they meant and where they were on his body. The process of designing and placing these markings was a tough one but I think they are one of Rocky's coolest features — lots of little stories and info about him."
The guide shows Rocky's limbs from multiple angles, with annotation lines and short descriptions identifying each marking. Taken together, they cover six distinct areas of his life and culture.
The family crest is perhaps the most unusual design choice in the guide. It is divided across two opposite limbs, one half on each, so the full crest only becomes legible when those two limbs are brought together. Blake labels one side "Family crest - when paired with opposite leg/arm" and notes the matching half on the other side of the body.
Another limb carries markings related to sound production labelled "Sound making - Lower tone at top, Higher pitch at bottom." Eridians communicate through musical chords and tonal frequencies and in the story Grace has to build a translation machine to hold a conversation with Rocky. The pitch markings on his limb appear to function as a tonal reference, a scale he can physically feel which makes practical sense for a species that navigates entirely through echolocation and sound.
There are small raised markings described as "Small tribal scars - similar to African tribal markings when seeds are placed under skin" draw explicitly on real-world African scarification traditions where subdermal implants create raised keloid patterns used as cultural identity markers. On Rocky, these serve a similar function as markers of cultural belonging and community.
Rocky also carries a marriage symbol of two interlocked circles permanently carved into his limb, denoting that he has a spouse (Adrian as Grace names them) back on Erid. The marking cannot be removed. It is confirmed in Weir's novel as well and the film's design team chose to encode that with the symbol.
Across several limbs, the guide identifies tool markings including a measuring tool, geometry and angle references, and a ruler. Tom Blake's guide labels these specifically as Base 3 tools - "Base 3 Geometry / Angle tools" and a "Base 3 Ruler." This is a notable difference from Andy Weir's original novel, where Eridians use base 6 mathematics, a senary system that makes sense given their biology as they have six counting fingers, three per hand on the two limbs that are free while the other three support their weight.
Whether the film's design team adapted this to base 3 as a simplification or for another reason is not explained in the guide.
A marking near the upper portion of one limb denotes his ship rank, described as "Symbol of Rocky's rank/position within his ship." Rocky holds a specific crew position aboard the Eridian vessel Grace calls the Blip-A and that position is recorded permanently on his limbs.
The final and most narratively significant set of markings are the star maps. Multiple annotation lines in the guide point across the last limb grouping to a single label: "Star Maps - Map of Rocky's Mission showing the Petrova Line and Astrophage."
The visual design from book to film was incredibly well done
The markings in Blake's guide connect back to Weir's broader vision of Eridian civilization of a society with cultures and histories as detailed as any human ones. They use base 6 mathematics and communicate through chords and tones so efficiently that Eridian speech carries roughly six times the information of human speech in the same amount of time.
Getting Rocky onto screen took over a year and nearly 300 designs. The physical puppet was built by creature designer Neal Scanlan, whose previous work includes numerous Star Wars creatures, and performed by puppeteer James Ortiz leading a team of five (nicknamed the Rockyteers) across nearly the entire six-month London shoot. Directors Phil Lord and Chris Miller chose practical puppetry specifically so Ryan Gosling had a real scene partner rather than a green screen reference point. The carvings Blake placed on Rocky's body existed on that physical object present on set.
The film also includes a sequence with no equivalent in the novel: Grace boarding the Blip-A and seeing the interior of Rocky's ship. In the book, Grace never leaves the Hail Mary while the ships are docked. The film's production designer Charlie Wood designed the Blip-A's interior around Eridian echolocation, so every surface, texture and hanging element was conceived to be perceived through sound. It is one of the more considered pieces of world-building in the film, constructed from the actual logic of what a species without vision would build.
The farewell scene is also where the markings become most directly active. Puppeteer Ortiz noted in interviews that there was a design on Rocky's inner forearm that the team had not found a place for during filming. When Rocky grazed it with a leg during the goodbye sequence, it produced a musical sound.
With the film recently becoming available digitally on Prime Video, Apple TV, and other platforms, there has never been a better time for a rewatch. now that you know what you are looking at, Rocky's limbs are worth pausing on every time they are on screen.
Add us as a preferred source on Google