You need a marquee. And a blink.

marquee.js

/**
 * This marquee stuff is deliberately low-tech. Use at your own risk. Licensed under whatever license you need.
 *
 * Usage: `marquee();`
 */

function marquee(behavior, direction) {
  var behaviors = {
    scroll: 'scroll',
    slide: 'slide',
    alternate: 'alternate'
  };
  var directions = {
    left: 'left',
    right: 'right',
    up: 'up',
    down: 'down'
  };

  var marquee = document.createElement('marquee');
  if (behavior && behaviors.hasOwnProperty(behavior)) {
    marquee.behavior = behavior;
  }
  if (direction && directions.hasOwnProperty(direction)) {
    marquee.direction = direction;
  }
  marquee.innerHTML = document.body.innerHTML;

  document.body.innerHTML = '';
  document.body.appendChild(marquee);
  console && console.log('Enjoy.');
}

function blink() {
  var html = document.body.innerHTML;
  var is_blink = false;
  setInterval(function() {
    if (!is_blink) {
      document.body.innerHTML = '';
      is_blink = true;
    } else {
      document.body.innerHTML = html;
      is_blink = false;
    }
  }, 500)
  console && console.log('Enjoy.'); 
}

Very clever implementation of <blink />, but what is it doing in marquee.js‽ ;)

Add blink.js to Useless-JS!