I'll start:
I still remember this one from when I was like three and the word "chilly" (coldish) made me think of red jello. It scared me that badly at the time.
My parents pulled into the driveway after a shopping trip. We headed up the steps to the door in the garage. My parents went before me. I turned around at the door and saw....a very odd creature.
It had the build of an octopus, except it was walking stiff-legged and looked as though it were made of play-dough. It was black. It's bulbous head was decorated with facial features that looked as though painted by indians, in clown-like colors. I backed away slowly, scared out of any kind of wit that a three-year-old might have. It collapsed all of a sudden, right at my feet. It's head made a hollow sort of sound, like an empty plastic container. I ran inside and woke up.
This dream scared me so bad I ran into my parents room and slept with them the rest of the night.
Your turn!