Yeah, I'm on the page with Zigsta on this one. I think this is definitely -2.
Bowser obviously excels on the ground in comparison to Jigglypuff, that's a given. Jigglypuff has the ability to juggle Bowser pretty decently I guess, but Bowser's FAir and NAir serve as a good "combo" breaker in between her attacks. That being said, getting Bowser in the air will probably be the most difficult thing you can try to do if you're not using pound.
Seriously. Use Pound, because it'll be much better pressure than any of your aerials, especially against a shield camping Bowser. Bowser can just swat her away with FTilt ordinarily, but with pound I think we trade at the worst or something like that. Pound also eats Bowser's shield up, and it always forces us to angle it at some stupid way so we don't get poked terribly.
I think FD is a contender for Bowser's best option because of the amount of room we have on that stage. First of all, there are no platforms, so we are at risk of removing one of Bowser's best abilities (command grab > all of Jigglypuff's options when you're above us on a platform).
Aside from that, the glaring problem is the grab releases, and you're not as difficult to grab as say...Wario, or something. Retreating aerials or Pound can do a bit of work, but a grounded Bowser is such a menace to Jigglypuff lmao. We kill you at like 60 flat with UAir, which isn't that difficult to set up or do. On a ground release, we have the basic jab and FTilt I believe.
For that issue with the Finnish Bowser, I have a feeling that Jigglypuff can just DI into Bowser when he jabs, and then use rest before he FTilts you, because FTilt isn't super fast..it just gets the job done really nicely imo. I could be wrong, I just feel like jab-cancelling is so heavily flawed out of a grab release unless RCO lag is involved or the Bowser player is reading your bad habits or something.
And a small note, if you get Bowser offstage, of course, take advantage of that and try to gimp him to the best of your ability. But, what happens if Bowser just stays put in the center of the stage? It takes a lot of work to get Bowser to the edge at that point, especially because Jigglypuff does like...nothing at lower percents. lol
From the way I see it, Jigglypuff just has to play a weaving game and rely on hard frametraps or occasional gimps to kill us or get us to kill percents. For Bowser, all we have to do is land 4 moves or 4 Klaws and just get you with a hard attack or GR => UAir, and it's over. :/
Stage wise, I personally would CP FD, because of what I listed earlier and the argument about being in the center of the stage. I don't know what I would counterpick as Jigglypuff, because BF would save you from the UAir release (maybe? I forget how far up Jigglypuff goes--if she goes above the top platform, then she's safe. Otherwise...), but the problem with CPing us to BF is that it's our best stage as well. I'm sure Jigglypuff has some nasty stuff on BF anyway lol
edit: Jay, no Jigglypuff should be getting away with a rollout lol, that's the easiest move to react to. And if your reaction time is bad, just shield and UpB on reaction, or Klawhop over it.
I did get ****ed by a frametrap before off of a rollout ;=;