MediaWiki:Wikia.js

var background = [
    'url(https://vignette.wikia.nocookie.net/gummy-drop/images/e/e5/SydneyNewFullBlur.png/revision/latest?cb=20190207104849) 0 0 / cover no-repeat fixed',
    'url(https://vignette.wikia.nocookie.net/gummy-drop/images/3/3a/TokyoNewFullBlur.png/revision/latest?cb=20190207104849) 0 0 / cover no-repeat fixed',
    'url(https://vignette.wikia.nocookie.net/gummy-drop/images/d/da/SanFranciscoFullBlur.png/revision/latest?cb=20190207104849) 0 0 / cover no-repeat fixed',
    'url(https://vignette.wikia.nocookie.net/gummy-drop/images/c/c5/NewYorkFullBlur.png/revision/latest?cb=20190207104849) 0 0 / cover no-repeat fixed',
    'url(https://vignette.wikia.nocookie.net/gummy-drop/images/8/87/ParisFullBlur.png/revision/latest?cb=20190207104849) 0 0 / cover no-repeat fixed',
    ];
var final = background[Math.floor(Math.random() * background.length)];
$('body.skin-oasis').css({
   'background' : final
});