<div class="slider-thumb"></div>
body {
  height: 100vh;
   background: linear-gradient(90deg,#e52e71,#ff8a00);

}

.slider-thumb::before {
	position: absolute;
	content: "";
	left: 30%;
	top: 20%;
	width: 450px;
	height: 450px;
	background: #17141d;
	border-radius: 62% 47% 82% 35% / 45% 45% 80% 66%;
	will-change: border-radius, transform, opacity;
	animation: sliderShape 5s linear infinite;
	display: block;
	z-index: -1;
	-webkit-animation: sliderShape 5s linear infinite;
}
@keyframes sliderShape{
  0%,100%{
  border-radius: 42% 58% 70% 30% / 45% 45% 55% 55%;
    transform: translate3d(0,0,0) rotateZ(0.01deg);
  }
  34%{
      border-radius: 70% 30% 46% 54% / 30% 29% 71% 70%;
    transform:  translate3d(0,5px,0) rotateZ(0.01deg);
  }
  50%{
    transform: translate3d(0,0,0) rotateZ(0.01deg);
  }
  67%{
    border-radius: 100% 60% 60% 100% / 100% 100% 60% 60% ;
    transform: translate3d(0,-3px,0) rotateZ(0.01deg);
  }
}

External CSS

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External JavaScript

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