<div class="icon">🔥</div>

.icon {
  background-image: url("https://assets.codepen.io/18515/grumpy.png");
  background-position: center center;
  background-size: contain;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

body {
  margin: 0;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 100px;
}