http://www.texassnakes.net/YellowBellied.htm
That’s my husband’s company website! :) And yes, the snake in the first post is the yellow-bellied water snake.
And no, the yellow does not extend that far down the snake's body.
Only about six inches or so below the head, which has a completely different shape.
It's a cottonmouth.
Y'all go ahead and respect 'em, I'll continue killing 'em.