If I may provide a rebuttal towards the above post, I'm going to take a look at the major arguments presented…
Is it a type of image? So, now we want an entry about “pictures of boobies”. Why not one about “pictures of cars” or “pictures of computers”?
Because this is something that's prevalent with animators – especially ones one the internet (which, golly happens to be what this site is mainly about). If you pull up a cartoon by Egoraptor or SpazKid and there's a woman in there, odds are they're going to be some jiggling involved.
Is it an animation style? KYM doesn’t document animation styles, that’s OLD MEDIA. Unless you want to expand and make pages on “cel shading” and “24fps”.
I wouldn't call it an Animation Style so much as I would call in an Animation Trend. It isn't present in absolutely everything, but it's pretty prominent in the medium.
Is it an inside joke? Catchphrase? No examples have phrases, or even words.
"Gainaxing" is an inside joke for Anime fans for exaggerated breast movement, and "Jiggle Physics" is the same thing regarding Video Games. The latter might as well be called "Dead Or Alive Syndrome" or something. I believe there are a couple of Demotivational Posters among the many images featured within the Gallery.
If it’s a meme, what is its origin? How has it evolved? It’s just fanservice. It’s been around as long as all media, forever.
Not in animation, it hasn't. True, a handful of the images in the Gallery aren't animated, but most of them are, and that's what the entry is trying to support.
If it’s a subculture, what is the fanbase? Horny dudes? Overly global. Why don’t we make an entry about the “food” subculture? Man, I am such a foodbro.
A quick tangent: I'm pretty sure that we have tons of pages on specific foods already, so this is a moot point. Come to think of it, a "Food" article may actually be necessary.
Back on topic: I will give you this point. It doesn't seem like we have pages relating to people being fond of sexuality in general. Oh, wait just a minute… Did you forget that there's a Gallery for Asses? And don't even get me started on how much porn is in this Gallery.
You also seem to have defeated your own point by mentioning an existing Meme that supports the idea that there should be a gallery related to "sexy" stuff. I implore you to take a look at ten or so images on the "Jiggle Physics" page and tell me exactly how well they would transfer.
For the record, I'm not trying to be combatative so much as I'm trying to prove that the article legitimately does have a place here.