This Robot Brings Project Hail Mary’s Rocky to Life

Project Hail Mary has taken the box office by storm this spring and has left moviegoers wishing they had a friend like the five-legged, alien engineer called Rocky. YouTuber Leviathan Engineering doesn’t anticipate being able to take a trip to planet Erid any time soon, so he built a robotic clone of Rocky instead. It may not be an actual alien, but it does talk just like the real deal. As a bonus, this one doesn’t need a high-pressure, ammonia-rich atmosphere to survive.

The build combines hobbyist robotics, 3D printing, and modern AI tools to recreate one of science fiction’s most beloved recent characters in physical form. Rather than simply constructing a static prop, the creator wanted Rocky to move, gesture, and hold conversations dynamically, much like the character seen on screen.

This was made possible with a Raspberry Pi 5 that handles communication with large language models such as Claude and Gemini. The computer also manages the robot’s input and output systems while coordinating movement through a dedicated servo controller. Because the enclosed torso leaves little room for airflow, an active cooling system with a heatsink and fan was installed to keep temperatures under control during operation.

Movement comes from seven MG996R metal gear servo motors mounted throughout the limbs and torso. The servos are connected to a PCA9685 driver board, which allows precise control without overloading the Raspberry Pi’s GPIO pins. An external power supply feeds the motion system separately, avoiding the power limitations that would come from attempting to run the motors directly from the Pi.

The robot’s body was entirely 3D-printed using color-shifting filament selected to mimic Rocky’s unusual appearance. Instead of painting the parts afterward, the creator carefully oriented prints vertically so the color gradients would remain visually consistent across the body. Hollow internal cavities were designed into the parts to make room for wiring, servos, and the onboard computer hardware.

Rather than relying on pre-programmed voice lines and canned animations, the builder used tool-calling features that allow the language model to trigger physical actions on its own. During conversations, the AI decides when Rocky should perform gestures such as arm movements or celebratory motions based on the context of the interaction.

To complete the illusion, the system prompt was heavily customized to reproduce Rocky’s distinctive speaking style, including his habit of ending statements with “Question” and repeating enthusiastic phrases like “Happy Happy Happy.”

The finished robot may not have the engineering genius of its fictional counterpart, but it comes very close to capturing Rocky’s personality. For fans still leaving theaters wishing the alien engineer were real, this project might be the next best thing.