On Complete Event

var config = {
    type: Phaser.AUTO,
    parent: 'phaser-example',
    width: 800,
    height: 600,
    backgroundColor: '#026bc6',
    pixelArt: true,
    scene: {
        preload: preload,
        create: create,
        extend: {
            releaseItem
        }
    }
};

var game = new Phaser.Game(config);

function preload ()
{
    this.load.atlas('knight', 'assets/animations/knight.png', 'assets/animations/knight.json');
    this.load.image('bg', 'assets/skies/clouds.png');
    this.load.spritesheet('tiles', 'assets/tilemaps/tiles/fantasy-tiles.png', { frameWidth: 64, frameHeight: 64 });
}

function create ()
{
    //  The background and floor
    this.add.image(400, 16, 'bg').setOrigin(0.5, 0);

    for (var i = 0; i < 13; i++)
    {
        this.add.image(64 * i, 536, 'tiles', 1).setOrigin(0);
    }

    this.add.text(400, 8, 'Click to play animation', { color: '#ffffff' }).setOrigin(0.5, 0);

    //  Our attack animation
    var animConfig = {
        key: 'attack',
        frames: this.anims.generateFrameNames('knight', { prefix: 'attack_A/frame', start: 0, end: 13, zeroPad: 4 }),
        frameRate: 12
    };

    this.anims.create(animConfig);

    var lancelot = this.add.sprite(400, 536, 'knight', 'attack_A/frame0000')

    lancelot.setOrigin(0.5, 1);
    lancelot.setScale(8);

    //  Event handler for when the animation completes on our sprite
    lancelot.on(Phaser.Animations.Events.ANIMATION_COMPLETE, function () {

        this.releaseItem();

    }, this);

    //  And a click handler to start the animation playing
    this.input.on('pointerdown', function () {

        lancelot.play('attack', true);

    });
}

function releaseItem ()
{
    var item = this.add.image(500, 500, 'tiles', 54);

    this.tweens.add({
        targets: item,
        props: {
            y: {
                value: -64,
                ease: 'Linear',
                duration: 3000,
            },
            x: {
                value: '+=128',
                ease: 'Sine.inOut',
                duration: 500,
                yoyo: true,
                repeat: 4
            }
        },
        onComplete: function () {
            item.destroy();
        }
    });
}