I was going to say, most of the Catholics I knew would have restrictions during lent, sometimes not eating any meat. There have been Christian groups throughout history that didn't eat meat because that would mean killing, it's weird to me how many people are against vegetarianism or veganism in a predominantly Christian nation.

In the XVII century church officially classified beaver as fish, based on the Thomas Aquinas classification of living beings based on their habitats. Though the precedents were older, some decisions at local level were reaching at least XV century. The reason was of course that monks (especially Cistercians) tried to circumvent the friday fasts by the explanation that beaver tail is covered with scales therefore specifically the tail is a fish and can be eaten in friday.

Are birds land animals? What about a duck?