Can we just talk about Asterix? Far less controversial.
I get the feeling a few people take this a little seriously!
It all comes down to personal preference but for me the only pro-vegetarian argument that holds any water is the carbon-efficiency one advocated by redpanda above. And I'm of the view that one can make personal carbon cutbacks in other areas if one wishes. I want meat. As Sun points out, it's a natural part of our diet. The fact that Paix (who otherwise seems to have a very well balanced diet, given the absence of one of the human diet's major components) feels the need to take B12 supplements is the giveaway that the diet is
not properly balanced. A balanced diet doesn't require artifical supplements.
I have no problems with eating any animal - with just three caveats:
1) They should be reared and despatched as humanely as possible (while I am pro-meat, I am anti hunting with hounds, for example)
2) They should not be from endangered species (although I am very happy to eat rare domestic breeds, as eating them encourages their commercial breeding and actually increases their security!)
3) They should not be humans! (Chlidonias' societal convention kicks in!)