Edit in JSFiddle

var BoxView = Backbone.View.extend({
    tagName: 'div',
    className: 'color-box',
    render: function() {
        this.$el.html('Hello World!');
        this.$el.hide();
        return this;
    }
});

var BodyView = Backbone.View.extend({
    el: 'body'
});

var body = new BodyView();
var box = new BoxView();
body.$el.append(box.el);
box.render();
box.$el.show('slow');

.color-box {
    width: 100px;
    height: 100px;
    background: #F00;
}