Not me crowdsourcing ideas for my silly ideas because I'm still creatively indecisive after months of procrastinating and dealing with IRL stuff-

Anyways, here's a collection of methods of mass expansion scenarios (scenarios in which furs become inflated en masse). I chose to list five different scenarios I'm fond of, but just couldn't decide for sure on for if I wanted to make a real story about it. Listed, they are:

CONTAGIOUS AGENT: A contagious virus or chemical agent (most likely leaked from a lab) causes people to puff up at an exponential rate. This makes for a simple, slow-building scenario, but it may hit too close to home...
ROBOT TAKEOVER: An AI system decides that the world would be a lot better if everyone was big and round, and uses types of robots to achieve its goal. This is already an idea I've posted about, but it's also hard to plan (especially considering my present-esque world), and may also hit too close to home (unless you have more than one brain cell and can distinguish between real GenAI and cartoony self-aware AIs).
ALIEN INVASION: An alien race arrives to Earth intent on inflating everyone. This is basically a Robot Takeove scenario from space. The only real drawback, aside from a desire to keep the cause artificial, is: why would an alien race need to blow up everyone?
SUPERVILLAIN: A supervillain or supervillainess decides to cause mischief for the world by causing everyone to puff up like blimps! This in of itself would need another scenario to carry out their plot, but it's also the most appropriately cartoony out of the five.
FOOD/DRINK TREND: A super-carbonated beverage or self-blowing bubblegum becomes the next big trend, being desired by billions; kind of like a kink-centered version of Prime. The big drawback with this is getting enough people to ingest the product (unless it was contagious somehow, or a meme that makes everyone "need" it).

So, which is your favorite scenario, and why?