Bees, wasps, hornets, dirtdobbers, yellow jackets, ect. I've never been stung by one, but they seem to have a way of finding me. The more flight an insect is capable of, the more they freak me out. I'm terrified of them!
Also, the ocean. I don't know why, but the thought of like being in the ocean and having say a whale swim up next to me sounds like one of the creepiest things ever. Actually just the thought of being in or riding a boat on deep water freaks me out. I don't know why, I can swim pretty good and I love a good swimming pool...but the ocean freaks me out!