When I was a kid, my parents bought this wooden rocking horse. I don't remember having any particular thing against it (then again I was like 4 at the time), but what I do remember are the nightmares that occurred frequently because of it. In my dreams, the rocking horse would chase me through my house, and when it finally caught me, it started eating my hands. It got to where I couldn't fall asleep without putting my hands beneath my pillow (a habit which has persisted to this day even though the dreams are gone), but the dreams persisted nonetheless. It got to the point where I was too afraid to get anywhere near the horse, and my parents decided to sell it, and the dreams stopped afterward.
Another more general nightmare that occurred throughout my teenage years was a dream where I was being chased by random people (didn't know who they were, never got a good look). I would start running in the opposite direction and suddenly fall. I would scramble away, trying to escape, but I never could bring myself back to my feet. One time it was a pack of wolves instead of a person. Regardless of who was chasing me, it was always a terrifying experience.