Deep, moving water - better known as the ocean. It's not the sharks, jellyfish or sea lice. It's the fact that it's deep, very large and uncontrollable. I am not a strong swimmer and if anything has a strong current I tend to avoid it. I am the person that will panic in a rip, and drown. I hate it. Snorkeling is okay if I am with people, and the water is less than 6-8 metres deep, and I am within a short distance of a shoreline or sand bank. When I see people who cave dive in the ocean, I shudder. Small confined space, under water? My worst nightmare.
The moment(s) that those very close to me die. I am not afraid of death, but there's something in me that brings on panic when I imagine those who I am close to, passing. Namely my parents and my brother and sister, my hubby and my dogs. I think you always tell your friends how you feel about them, but with your family you assume it's a given. How many people say, "they know I loved them" when someone dies? Really? Did you tell them or did you just assume because you saw them all the time? I think also, because it's this feeling that your mum and dad and your brother and sister are always going to be there, in the background. You forget that they're people too, with their own destiny and it has nothing to do with how long you think they should be there.
The above mentioned being hurt or frightened, in any way, shape or form. Extra points if there is someone responsible for it and they did it on purpose. I am not above seeking those out who've hurt those people and making them feel the same fear the inflicted on someone else.
Leeches. Anything that can attach itself to you, and is difficult to remove. Ticks also.