If there is a documented medical need, and the animal can be reasonably accommodated and would not pose a disruption or risk to the flight or to other passengers – yes. But I’m not sure a peacock could be reasonably accommodated or would not pose a risk or disruption. And everybody could claim their pet as emotional support. I’m not sure that, in and of itself, is justification to allow folks to carry their pets wherever animals would not normally be allowed.