The Terrapin

"A young boy, Victor... is emotionally abused by his difficult, haughty mother, an illustrator of children's books. The terrapin of the title, a small tortoise purchased by his mother for cooking, suffers an agonizing death when she drops it into the boiling pan. This event pushes young Victor over the edge—he believes he heard it scream—and during the night he butchers his mother with a kitchen knife for revenge. The story ends while he is being examined by doctors in a psychiatric hospital." -- Wikipedia