animate.css/source/flippers/flipInX.css

@keyframes flipInX {
    0% {
        transform: perspective(400px) rotateX(90deg);
        opacity: 0;
    }

    40% {
        transform: perspective(400px) rotateX(-10deg);
    }

    70% {
        transform: perspective(400px) rotateX(10deg);
    }

    100% {
        transform: perspective(400px) rotateX(0deg);
        opacity: 1;
    }
}

.flipInX {
	backface-visibility: visible !important;
	animation-name: flipInX;
}