These are water puppets (or Múa rối nước, if those characters display correctly on your screen) in Hanoi, Vietnam. If you search on YouTube for “water puppet,” you can find a ton of videos of this same kind of performance. This one, however, was the only one I could find where you could really see what was going on. The swimming dragons are particularly cool. To distill the Wikipedia entry on this topic, this type of performance has been going on for at least seven or eight hundred years, and it usually features humorous folk tales.

Here is a second video with a nice shot of a humorous bit involving a fisherman, starting about 45 seconds in.