<div id="background">
        <div id="box">
            <div class="button">
                <img src="alien.png" type="button" id="my-button">
                <br>
                <p>Click The Alien!</p>
            </div>
        </div>

<script>
var myData = {

        1: {
        imageUrl: "8.gif",

        },

};

function changeImage() {
        var randomNumber = Math.floor((Math.random() * 1) + 1);
        document.getElementById("background").style.background = "url('" + myData[randomNumber].imageUrl + "')";
        document.getElementById("text-box").innerHTML = myData[randomNumber].text;
}
    document.getElementById("my-button").addEventListener("click", changeImage);