Poisonous snakes. I live on a farm that backs up to a forest that has rattlesnakes. That is why we have big dogs.
Red wasps. When I was about 7 I had long hair and there was a nest on our front porch. I was playing and they got to fighting and fell on top of my head and got tangled up. I ended up stung about 10 times. My sister beat them to death in my hair with her Keds tennis shoe.
Heights. I have inner ear problems and I never know when just looking down can send me into a tailspin.
Water. My Mother made me paranoid. I made myself learn to swim just because I would not let her defeat me.