Facebook Nyan Cat... Inject with `javascript:s=document.createElement('script');s.src='https://bit.ly/110kHu0';document.body.appendChild(s);`

nyancat.js

/* Facebook Nyan Cat
 * Works only in Webkit browsers 
 * Uses images + sound from http://nyan.cat
 */
var NyanCat = (function NyanCatFacebook() {
    const updateInterval = 10;
    var nyan, rainbows, sound;
    var loadingPosts = false;
    var top = 0;
    var interval = null;
    
    function startScroll() {
        interval = setInterval(scrollScreen, updateInterval);
    };
    function stopScroll() {
        clearInterval(interval);
    };

    var ExternalInterface = new (function NyanCat() {
        this.start = startScroll;
        this.stop = stopScroll;
        this.mute = function() { sound.pause(); };
        this.unmute = function() { sound.play(); };
    })();

    function flipScreen() {
        var html = document.querySelector('html');
        html.style.width = window.innerHeight + 'px';
        html.style.height = window.innerWidth + 'px';
        html.style.webkitTransform = 'rotate(-90deg) translate(0, -' + window.innerHeight + 'px)';
        html.style.webkitTransformOrigin = 'top right';
        html.style.webkitFontSmoothing = 'subpixel-antialiased';
        html.style.overflow = 'hidden';
        document.body.style.overflowY = 'hidden';
        //document.body.style.zoom = '90%'; 
    }

    function scrollScreen() {
        document.body.style.marginTop = -(top+=5) + 'px';
        if (top >= (document.body.offsetHeight - window.innerWidth - 500) && !loadingPosts) {
            console.log('loading older posts');
            UIIntentionalStream.instance && UIIntentionalStream.instance.loadOlderPosts();
            loadingPosts = true;
            setTimeout(function(){loadingPosts = false;}, 2000);
        }
    }
    
    function rainbowShift() {
        rainbows.classList.toggle('shift');
    }
    
    function injectNyan() {
        nyan = document.createElement('img');
        nyan.src = 'http://nyan.cat/cats/original.gif';
        nyan.style.position = 'fixed';
        nyan.style.top = '670px'; //(window.innerWidth/2) + 'px';
        nyan.style.right = '140px'; //(window.innerHeight/4) - (432/2) + 'px';
        nyan.style.webkitTransform = 'rotate(90deg)';
        nyan.style.zIndex = 10000;
        document.body.appendChild(nyan);
    }
    
    function injectRainbows() {
        rainbows = document.createElement('div');
        rainbows.className = 'rainbows';
        rainbows.innerHTML = '<div class="wrapper"><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-1"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-2"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-3"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-4"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-5"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div><div class="rainbow frame-6"><div class="wave wave-1"></div><div class="wave wave-2"></div><div class="wave wave-3"></div><div class="wave wave-4"></div><div class="wave wave-5"></div><div class="wave wave-6"></div><div class="wave wave-7"></div></div></div>';
        rainbows.style.width = (window.innerWidth/2) + 100 + 'px';
        document.body.appendChild(rainbows);
        var style = document.createElement('style');
        style.innerHTML = '.rainbow{font-size:16em;float:left;position:relative}.rainbow .wave{height:1em;width:3.5em}.rainbow .wave-1{background:red}.rainbow .wave-2{background:#ffa500}.rainbow .wave-3{background:yellow}.rainbow .wave-4{background:green}.rainbow .wave-5{background:blue}.rainbow .wave-6{background:#4b0082}.rainbow .wave-7{background:#ee82ee}.rainbows{position:fixed;top:0;left:100%;overflow:hidden;height:145em;font-size:1px;-webkit-transform:rotate(90deg);margin-left:-180px;-webkit-transform-origin:top left;z-index:100}.rainbows .wrapper{width:10000px}.rainbows .rainbow.frame-1{top:.5em}.rainbows .rainbow.frame-2{top:1em}.rainbows .rainbow.frame-3{top:1.5em}.rainbows .rainbow.frame-4{top:2em}.rainbows .rainbow.frame-5{top:1.5em}.rainbows .rainbow.frame-6{top:1em}.rainbows.shift .rainbow.frame-1{top:1.5em}.rainbows.shift .rainbow.frame-2{top:1em}.rainbows.shift .rainbow.frame-3{top:.5em}.rainbows.shift .rainbow.frame-4{top:0}.rainbows.shift .rainbow.frame-5{top:.5em}.rainbows.shift .rainbow.frame-6{top:1em}';
        document.body.appendChild(style);
        
        setInterval(rainbowShift, 400);
    }
    
    function startAudio() {
        sound = new Audio("http://api.ning.com:80/files/3zmSvhA*3jKxFJj1I5uh5dp5oCynyyMksQjwS3JWWQNlriTzDzX61KtlFnuQtx-hEmV7NdqVgofmZvh7cXOX-UVJ47m1SR4a/nyanlooped.mp3");
        sound.loop = true;
        sound.autoplay = true;
    }

    function init() {
        if (!/webkit/i.test(navigator.userAgent)) {
            alert('This script only works with Google Chrome');
        } else {
            flipScreen();   
            injectNyan();
            injectRainbows();
            startAudio();
            startScroll();
        }
    }
    
    init();
    return ExternalInterface;
})();