Abstract Many migratory fish populations are declining, threatened by human‐induced pressures such as habitat loss and fragmentation caused by dams, roads, land use change, climate change and pollution. However, public awareness of fish migration and associated human pressures remains limited. It is important to communicate about hard‐to‐see and complex environmental topics and issues, such as fish migration, with young people, who stand to be the most affected by ongoing global changes. Young people are also at a critical stage in their attitude formation and may be particularly receptive to learning enrichment and engagement for behaviour change about environmental issues. Arts‐based methods can be particularly effective in fostering broad personal connections with nature, especially for complex topics like fish migration. The collaborative and creative processes involved in developing such media often lack critique, which limits learning from previous experiences. In this article, we reflect on the co‐creation of the Shout Trout Workout (STW), a lyric poem, comic and music video for 8‐ to 14‐year‐olds, designed to entertain, engage and enrich learning about migratory fishes and aquatic environments. We chart the process of creation, including conception of ideas, writing the poem, fact‐checking and developing the storyline with scientists and creating a comic and music video with visual artists and musicians. We explore some of the challenges and merits of collaborative working, consider the impacts of the COVID‐19 pandemic on the creative and initial engagement process and share what we learned about creative input, communication and respect. We also discuss how the experience shaped our thoughts about the nature of co‐creation itself, and how in creating STW, collaborators contributed to the process in multiple, nuanced and unanticipated ways (e.g. artistic input, ideas, science, dissemination), representing a spectrum of co‐creative practice. We hope that sharing our experiences and reflections is useful and inspiring for other cross‐disciplinary collaborations, and for those who aim to create learning enrichment and engagement material about ecological processes and environmental issues for young people. A free Plain Language Summary can be found within the Supporting Information of this article.