CSS

blob without svg

/*   # HTML Code
  <span class="animeblob"> <span> */

.animeblob{
    position: absolute;
    top: 55%;
    left: 40%;
    height: 50vw;
    width: 50vw;
    transform: translate(-50%, -50%);
    background-color: grey;
    animation: animate_blob 6s linear infinite;
}  
@keyframes animate_blob {
    0%, 100%{
        border-radius: 40% 55% 70% 35% / 70% 30% 90% 40%;
    }
    25%{
        border-radius: 25% 35% 90% 55% / 90% 50% 70% 30%;
    }
    50%{
        border-radius: 25% 75% 60% 75% / 60% 70% 30% 80%;
    }
    25%{
        border-radius: 25% 65% 60% 65% / 50% 60% 60% 10%;
    }
}