Behemoth Steaks are one of the most sought after foods in Final Fantasy (I know they are mentioned as such in FFTA2, and I think in a couple of the other games as well). Rich in nutrients, and with a delicious taste, they are one of the greatest prizes of taking down the large beasts. It is small wonder that other creatures would find them equally appetizing. Since you get so much for a single kill and they are so high in nutrition, it is small wonder that they would be considered worth the risk for pack animals.

Oh, wait, Behemoths in XIII are mechanical.