I have molluscophobia. It's a bit annoying when I do some gardening or walking around in the countryside, as slugs and snails are basically everywhere.
I basically can't stand close to them or touch them. I always wear gloves when I'm touching plants or branches outside, just because I'm afraid of touching a slug, a snail, or any sort of worm or caterpillar. I don't have any strong reaction when I see one though, just an uncomfortable feeling.
As you might know, it's common to eat snails in France. I absolutely can't, and never tried.
My mother also told me stories of her childhood where the slime of fat red slugs were used to treat coughs. You would basically boil slugs, put them in a recipient to harvest the slime, and drink the mixture with some sugar. Of course, children weren't told about it until years later, but it was cheaper than buying medicine back then.
I'm not sure where this phobia originates from. I have memories of my parents taking my brother and I to walk in the Landes forest, and I'm pretty sure I stumbled upon huge snails at some point. I remember running away and seeing more slugs in the tall grass, but nothing more.
When I was around 12, a caterpillar fell from a tree on my shoulder, and I went absolutely berserk till it fell off. I remember the fear surging all over me and my inability to breathe, it was terrifying. I know some people that are afraid of dogs and cats, but even though it's easy to make fun of them, I assure you there is nothing funny about having any phobia, so it's best not to play with people's feelings. The fear can be so extreme it can lead to violent reactions, like epileptic seizures. I haven't been that afraid yet, but I'm convinced I could instinctively punch anyone trying to force me to touch a slug, even though I'm not a violent guy—never initiated a fight, and laughed it off when someone threw me a punch once.
I recently learned that slugs sometimes eat other slugs though, so I almost like them for that.