https://blogs.scientificamerican.com/thoughtful-animal/once-upon-a-time-the-catholic-church-decided-that-beavers-were-fish/

This is gold!

So in the 17th century, the Bishop of Quebec approached his superiors in the Church and asked whether his flock would be permitted to eat beaver meat on Fridays during Lent, despite the fact that meat-eating was forbidden. Since the semi-aquatic rodent was a skilled swimmer, the Church declared that the beaver was a fish. Being a fish, beaver barbeques were permitted throughout Lent. Problem solved!