Fungal mycelium-based materials are attracting increasing attention as sustainable bio-based materials, while their manufacturing process is still mainly limited to moulding technology. Here we present a process with additive manufacturing that integrates living fungal mycelium with extrusion-based printing to create ultra-lightweight, shape programmable biohybrid materials. A printable paste composed of living Fomes fomentarius mycelium, milled rapeseed straw, sodium alginate and water enables high resolution printing through a 1.6 mm nozzle. The subsequent controlled growth phase forms three-dimensional fungal composites with defined shapes. In addition, thick and continuous mycelia skins on printed scaffolds can be peeled off when needed to produce pure three-dimensional pure mycelium mats. Key process elements are a composite hydrogel formulation that balances printability with nutrient support for growth, a weekly mechanical compaction routine during cultivation to constrain aerial outgrowth and preserve designed geometry. Freeze-drying inactivation minimizes shrinkage while retaining filament and internal grid integrity. The printed structures show ultra-low bulk density and good mechanical behaviour with hydrophobic surfaces. This approach integrates living fungal mycelium and sustainable feedstocks into the additive manufacturing workflow, enabling programmable, scalable routes to biohybrid materials that promotes fungal mycelium from a mould-based material to a flexible design element in the sustainable materials engineering.