This article calls for transdisciplinary, experimental, and decolonial imaginations of climate change and Pacific futures in an age of great planetary undoing. Drawing from our personal and academic knowledge of the Pacific from West Papua to Samoa, we highlight the need for radical forms of imagination that are grounded in an ethos of inclusivity, participation, and humility. Such imaginations must account for the perspectives, interests, and storied existences of both human and beyond-human communities of life across their multiple and situated contexts, along with their co-constitutive relations. We invite respectful cross-pollination across Indigenous epistemologies, secular scientific paradigms, and transdisciplinary methodologies in putting such an imagination into practice. In doing so, we seek to destabilise the prevailing hegemony of secular science over other ways of knowing and being in the world. We draw attention to the consequential agency of beyond-human lifeforms in shaping local and global worlds and to the power of experimental, emplaced storytelling in conveying the lively and lethal becoming-withs that animate an unevenly shared and increasingly vulnerable planet. The wisdom of our kindred plants, animals, elements, mountains, forests, oceans, rivers, skies, and ancestors are part of this story. Finally, we reflect on the structural challenges in decolonising climate change and associated forms of knowledge production in light of past and ongoing thefts of sovereignty over lands, bodies, and ecosystems across the tropics.