Updated for 2020: Yes, it can be done! Here’s how.
Snippet demo:
#mydiv{ animation: changeBg 1s infinite; width:143px; height:100px; }
@keyframes changeBg{
0%,100% {background-image: url("https://i.stack.imgur.com/YdrqG.png");}
25% {background-image: url("https://i.stack.imgur.com/2wKWi.png");}
50% {background-image: url("https://i.stack.imgur.com/HobHO.png");}
75% {background-image: url("https://i.stack.imgur.com/3hiHO.png");}
}
<div id='mydiv'></div>
Background image [isn’t a property that can be animated][1] – you can’t tween the property.
Original Answer: (still a good alternative)
Instead, try laying out all the images on top of each other using position:absolute, then animate the opacity of all of them to 0 except the one you want repeatedly.