The target property of a KeyframeEffect interface represents the element or pseudo-element being animated. It may be null for animations that do not target a specific element. It performs as both a getter and a setter, except with animations and transitions generated by CSS.
 
In the Follow the White Rabbit example, whiteRabbit sets the target element to be animated:
 
const whiteRabbit = document.getElementById("rabbit");
const rabbitDownKeyframes = new KeyframeEffect(
  whiteRabbit,
  [{ transform: "translateY(0%)" }, { transform: "translateY(100%)" }],
  { duration: 3000, fill: "forwards" },
);
rabbitDownKeyframes.target;