What's the largest animal you can moraly kill without retribution

Following on from the meat eating thread the question above popped into my mind.

We all kill insects daily & nobody bats an eyelid.
Neither does anyone object to the killing of rats & mice, they're accepted as vermin & we make traps to facilitate their death.
If I however attempted to kill a hamster or gerbil most people would be repulsed, cuddly pets it seems are not execution fodder.
I can however catch a 20lb salmon & knock it over the head or were I a farmer then a badger would be acceptable prey.
I realise that if I worked in an abattoir I could kill numerous half ton cows on a daily basis but that's too specialised for this discussion, I couldn't just walk into a field & shot one in the head with a crossbow & think nobody would raise an objection.

So, I can act out my bloodlust on a big fish & expect no comeback from most reasonable members of society.

Now I fully expect the "All god's creatures are sacred" wagon to come rolling in but I invite you to peddle that bullsh*t somewhere else.

If I pay to go shoot a giraffe in Africa should it be anyone's business ?