A Snake in CSS

If you think the article has a terrible title, you are right. Moving on...

I spend a good amount of time on CodePen creating CSS artwork. It's relaxing for me and gives me an opportunity to try out crazy ideas and see what I can come up with. If you don't want to read it till the end, head over to my profile and take a look.

I have been doing these things for some time now but never wrote an article explaining any of them. So I thought to myself, let's do that and start with a simple one. A Snake!

Here's the final output.

How did I arrive here?

Heads Up!

• A snake's body size reduces towards the end.
• The slithering effect of a snake comes from the fact that different parts of a snake's body seems to be moving at different time.
  • For us, that means the body needs to be made of different parts that can move at different times.
• Center everything on screen.( Not so important! )

HTML

Just a bunch of blobs that I'll use to compose the body of the snake. The size of .blobs will reduce from top to bottom.

<!-- .blob*20 + TAB via Emmet-->
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>
<div class="blob"></div>

Boilerplate CSS

body {
  /*to center everything on page( the blobs ) and line them vertically*/
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;

  height: 100vh; /*so it takes up entire viewport height*/
  margin: 0; /*reset*/
  background: #333; /*a dark background*/
}

/*Basic styles for all blobs*/
.blob {
  border-radius: 50%;
  background-image: linear-gradient(
    to bottom right,
    hsl(30, 100%, 50%),
    hsl(50, 100%, 50%)
  );
  transform: translate3d(-40px, 0, 0); /*will be required later*/
}

Generating the body

Notice, there's no width and height property set to the blobs. I'll make the blobs squares of reducing sides using SCSS.

@for $i from 1 through 20 {
  .blob:nth-child(#{$i}) {
    //From Basics: the body parts need to move at different time for the slithering effect
    // the delay increases from upper body to lower body
    animation-delay: $i * 0.1s;

    //start with 20px as sides. As $i increases, the dimensions reduce.
    width: 21px - $i;
    height: 21px - $i;
  }
}

At this point, all you'll see is this.

The Animation

Looks like our snake's body is set and all the body parts are now centered on the page. I have also given the animation-delay to each of the .blobs.

What about the animation?

You see, it's easy to trick human eyes. If we move each blob horizontally the same amount, with same time duration but a little bit of gradually increasing delay, it feels like it's moving like a snake.

Don't believe me? Here's the video again. Keep your cusor on one of the blobs and you'll see that it only moves horizontally.

So let's do that.

@keyframes blob {
  50% {
    transform: translate3d(40px, 0, 0);
  }
}

I am moving each blob 40px towards X axis at 50% of the animation from it's original position(i.e. when X translate is 0. In our case that's the horizontal center of body). Remember the negative translate I applied earlier? That was done to make the overall snake appear at the center of the screen. Here's how it works.

// Movement of a blob.
Start          Original Pos.          End
-40px -------------- 0 -------------- 40px
-------------------Repeat-----------------

A .blob starts at -40px. Reaches 40px at 50% of the animation and then finishes off at it's original position 0 at 100% of the animation( If no 100% state is specified, the default state becomes the final state. ) All in all, it looks like each blob is oscillating between -40px & 40px positions.

Let's apply this animation to all the .blobs.

.blob {
  /*...*/
  animation: blob 1.3s cubic-bezier(0.785, 0.135, 0.15, 0.86) infinite;
}

• Each blob takes 1.3 seconds to complete the animation.( animation-duration )
• cubic-bezier(0.785, 0.135, 0.15, 0.86) specifies the animation-timing-function. If you don't know what that is, head over to mdn.
• The animation is going to run infinitely (animation-iteration-count);

Putting it all together!

See the Pen Funny Snake Loader 🐍 by Praveen Puglia (@praveenpuglia) on CodePen.

If you want, you can fork the pen and play around with different properties of the blob and make your own variant of the snake! A Cobra? A Rattle snake? Whatever!

Hope you enjoyed it.