The fish slapping dance

What is it that's so funny about these fifteen seconds?

The term "fish slapping"? The merry music? Michael Palin's knees-up jig? The little "smek" sound of the fish? The surprise ending?

I submit to you that it's the way Palin falls. Not only is it a steep drop - a one-foot drop wouldn't have been as funny, don't you think? - but there's almost a resignation to it that flailing arms and legs would have obliterated. Just turn and drop face-first and you'll have your high hilarity.

Oh, and the huge splash helps too.