Is it possible to make animated PNGs?

It seems like it doesn't, you might want to read this bit of info on it:

http://www.libpng.org/pub/png/pngfaq.html#animation

Not really. Your best bet is to make your animation into a gif file. It may not have the same amount of colors in its palette as a ong, but it can be animated and loads faster anyways. :)