I have packed fish and game in styrofoam with dry ice and carried on plane, both as carry on and in cargo compartment. If you do any carry on, airlines limit the amount of dry ice allow in passenger compartment, and you must label box as containing dry ice. I'm not sure about restrictions if shipped as baggage. I would bone it out freeze it, then package it, ship it as baggage in styrofoam with dry ice, again, check with airlines about limits of dry ice allowed. Antlers, you are on your own there, I have no idea how that is handled, maybe UPS. If you run into flight delays, all bets are off.