Mycelium, the root structure of fungi, turns out to grow into something close to styrofoam if you feed it the right waste material. This episode of Motherboard's Upgrade series goes inside the research and development labs working to turn fungus into a real alternative to petroleum-based plastic, following the scientists and engineers who grow mycelium into packaging, insulation, and building material. Interviews with the people running the experiments explain how the fungus is cultivated on agricultural byproducts like corn husks and sawdust, then shaped in molds and dried to lock its structure in place. The film treats this less as a novelty and more as an industrial proposition, weighing cost, scalability, and durability against conventional plastic. Lab footage of mycelium blocks being grown, cut, and stress-tested gives the process a tangible, hands-on feel rather than a hypothetical pitch, and the episode closes on the open question of whether this material can move from prototype to shelf.