Any snake is cannibalistic, you just don't normally hear about it in anything but Kings. They might not "eat" each other, but if one startles the other, he/she will bite and wrap in what looks like a feeding response and could possibly kill the other snake. I've never seen a BP try to consume another snake, with how picky they tend to be anyways, but it is a possiblity of killing the other during this season especially.