The animal that moves by slithering on the ground is "la serpiente." Serpientes are snakes that move by contracting and expanding their bodies in a side-to-side motion, allowing them to glide smoothly across surfaces. Snakes do not have legs, so they rely on this unique way of movement to travel on land.
Slithering is a distinctive characteristic of snakes that sets them apart from other animals like dogs, horses, and tigers, which move using their legs. By understanding how snakes slither, we can appreciate their adaptability and efficiency in navigating various terrains.
Therefore, the correct answer to the question is "O la serpiente." This choice reflects the specific mode of locomotion attributed to snakes as they slither along the ground.