milk snake: nonvenomous tan and brown king snake with an arrow-shaped occipital spot; southeastern ones have red stripes like coral snakes
chordate: any animal of the phylum Chordata having a notochord or spinal column
living rock: usually unbranched usually spineless cactus covered with warty tubercles and having magenta flowers and white or green fruit; resembles the related mescal; northeastern Mexico and southwestern United States