Tween Alpha

var config = {
    type: Phaser.WEBGL,
    parent: 'phaser-example',
    width: 800,
    height: 600,
    scene: {
        preload: preload,
        create: create
    }
};

var game = new Phaser.Game(config);

function preload ()
{
    this.load.image('turkey', 'assets/pics/turkey-1985086.jpg');
    this.load.image('face', 'assets/pics/bw-face.png');
}

function create ()
{
    var face = this.add.image(400, 300, 'face');

    var sea = this.add.image(400, 300, 'turkey').setAlpha(0);

    this.tweens.add({
        targets: sea,
        alphaTopLeft: { value: 1, duration: 5000, ease: 'Power1' },
        alphaBottomRight: { value: 1, duration: 10000, ease: 'Power1' },
        alphaBottomLeft: { value: 1, duration: 5000, ease: 'Power1', delay: 5000 },
        yoyo: true,
        loop: -1

    });
}