As plastic pollution is considered a potential geological marker of the Anthropocene, some living organisms have evolved and adapted into symbiotic relationships with polymers. The wicked problem of pollution and toxic exposure contributes to waste colonialism, which is inherent to the current state of climate and ecological emergency. From plastics to fungi and back again, this project speculates on the possibilities to decolonise plastic waste with the help of a plastic-decomposing fungus. My research prompts toward anthropo-de-centrism and multispecies storytelling as design methods to develop care for plastic waste. The project draws upon the complexity of fungi-plastics-humans relations and is supported by a transdisciplinary collaborative research focused on fungi cultivation. At the core of this practice, I relate the omnipresence of fungi and plastics to queer ecologies, and as such, I develop my design proposal with generative toxicity as theoretical and creative framework.  To materialise this, I propose a workshop bridging between local communities of designers and self-taught mycologists, in order to change the general opinion on plastic waste by focusing on hosting and care as forms of slow activism. The longer-term aim would be a systemic rebalancing of our permanently polluted world. Queer ecologies could therefore contribute to refine what sustainability means for design today by facilitating multispecies care and decolonising gestures.