The hardest part of a project like this must be holding a raw egg firmly inside something that is itself squishy. The maker tackled it with an inner egg-shaped ring carried on diagonal supports inside a light blue cubical wireframe. The ring is concave inside, which the maker says makes the hold more firm, and it stretches in one direction while pinching the egg in the perpendicular direction. That combination is credited with keeping the egg retained well.
The whole thing is printed in TPU 75A at 2.85mm diameter, on a Bambu H3C. The resulting cube is flexible enough to be squeezed and compressed in your hands, which I think is exactly what a part like this should feel like. A soft wireframe that still holds its shape around the egg seems like a well-judged balance.
For testing, a whole brown chicken egg was pressed into the central ring, and the maker worked up to drop heights of about 2.5m. The frame bounces repeatedly on landing while keeping the egg off the ground. It is not perfect, though: the egg does crack if it lands perfectly flat on the open egg side. That is the one clear trade-off in the design as it stands.
When the egg was cracked open afterwards, the raw yolk and white were revealed intact, so the surviving drops were genuinely gentle on the contents. The maker says the project was made for no particular reason, just a chance to try out TPU 75A, and honestly that is my favourite kind of build. Sometimes a silly idea is the best excuse to learn a new material.