i appreciate the art I see of human Perry the Platypus from Phineas and Ferb but also I believe that if you ship Perry the Platypus and Dr. Doofenshmirtz you should just full send and keep Perry the Platypus a platypus.
No reason for Dr. Doofenshmirtz to not kiss and marry him as a platypus in my opinion. Not even as a furry thing. I just think in the canon of the show itself it wouldn’t be weird. I think gay, human/secret-agent-platypus marriage is probably legal in the tristate area.