The disgusting Harry Potter every flavour beans. They had jelly belly jelly beans that tasted like dirt, grass, booger, vomit, ear wax, and others I can't remember.

Licorice. Anise flavored candy. It's disgusting.

Hersheys "chocolate". I spit it out, and a bit embarrassed, asked "could it gone bad during the flight?"

Well, obviously this stuff does taste like vomit, and Americans seem to be OK with that. Explains a lot about American behavior. If chocolate here would taste like that, we probably would have more mass shootings, too.

I tried some matcha mochi once. It didn't really taste good, but the worst thing about it was that it was just boring.

If I had to choose between leather belt flavoured licorice and vomit flavoured Hershey's. Licorice wins everytime.

Salted liquorice.

I had a Norwegian friend who waxed lyrical about this stuff. So when I saw it for the first time in a shop, I grabbed a packet to nibble on while waiting for my train.

Plain black liquorice is delicious and salt makes everything taste better, and the Norwegian seemed like a nice, relatively normal person who enjoyed other things I liked. This was a low risk choice of mid morning snack, I thought to myself.

I was wrong. So very wrong.

This stuff tastes like it was peeled off the bottom of a shoe after walking through the city all day. It's not salt either, it's freaking ammonium chloride.

To paraphrase the Wikipedia:

The mineral is commonly formed on burning coal dumps from condensation of coal-derived gases. It is also found around some types of volcanic vents. It is a product of the reaction of hydrochloric acid and ammonia.

And Scandi's put this on liquorice and like it. Even the kids. Madness. It took my all not to heave into a bin after trying it and like six cups of black tea to get the taste out of my mouth.

I gave the Norwegian the rest of the packet and he laughed at me while I watched him eat it because I looked so horrified.

First of all, licorice is good actually, though black jelly beans are trash.

One time I bought olive flavored gummies from the Asian market because I love olives and I was curious. Absolutely horrible, didn't even finish one.

American candy. Not American brand candy which different outside the US, but actuall American candy. It's all so bad quality and vile that it would never sell outside the US and not even be legal to do so in many places.

That's an easy one - Durian bonbons from China. Durian is also known as the "stink fruit". You need many hours to get that taste out of your mouth

I’m seeing a lot of black licorice mentions, but there’s a special hell for Läkerol’s menthol black licorice.

Licorice, that funny retro looking shit with the black and bright colors. They are as revolting to me as sushi

Related anecdote: When I worked an offshore rotation with people from all over the world, I made an effort to bring candy that I'd never seen outside of Scandinavia. It was always amusing to see people sampling candy I liked when they weren't used to the ammonium chloride branch of flavors.

And once I brought this:

Everybody who weren't Norwegian, Swedish, or Finnish (sadly we had no Danes on board) absolutely hated it. Especially the Americans and Brits.

Everyone except Mario, that is; a Croatian geophysicist. He loved them. His voice still lives rent free in my head over ten years later, saying "Sweet candy is for kids"

A few trips later I brought one of my favorites for basically the same result, but this time with Jim (from Illinois, iirc) complaining that it made his mouth physically hurt:

Mario loved that one even More.
The only thing everyone on board liked was the obscene amount of chocolate my navigator brought every trip.

But to answer the question: Twizzlers. I bought some when visiting the US a couple of years ago. It tasted like oily sweetener (as in, clearly not actual sugar). That's when I learned that American and European wine gum are flavored very differently.

Footnote: Durian and durian chocolate is quite alright once you get used to the slight farty smell from each packet you open.

American or South African chocolate products.

NOT an anti-American/-Saffer thing. They add butyric acid, which tastes like vomit to the rest of the world. (Accurate, as vomit contains it).

Presumably because the market there have been trained to expect that flavour for some reason. To the rest of us, a US or ZA origin is usually a sign to avoid.

Black licorice.

I firmly believe candy should be sweet; not bitter.