As an immersion into the underground of tropical forests, this work is a transdisciplinary entanglement nurtured by mycelia. In its greatest extent, it carries the fresh scent of earth and decomposition, and its tendency is to become compost. It brings together design, art, anthropology, and biology to investigate and exercise a design oriented towards sympoietic practices through the cultivation of fungi. Recognizing mycelium both as a metaphor and as matter that you can shape things with,the research aims to experiment with the possibilities and means of designing-with fungi, seeking less anthropocentric design perspectives that are more aligned with an ecosystemic logic. It is grounded in concepts such as Donna Haraway s sympoiesis and the passionate immersions of Thom Van Dooren et al., adopting a practice-theory methodology and following the research through design (RtD) method. The goal is to examine how biodesign processes can be more aligned with a biodiverse, multispecies, local, and relational approach, in contrast with the market standards to which conventional design usually caters – standards that follow the logic of monocultures. This research seeks to represent a path of learning and grounding, to generate and sow curiosity, empathy, respect, patience, and perhaps even encouragement to inhabit a planet of intense transformations and successive collapses — uncertain and insecure, yet still full of life.