Weird Creature in the Sky

When I was about 11-12 years old, I was walking towards a building where my mother works. It was a stormy day, a little bit dark and the clouds were wild. It didn't rain yet, and I was hoping to come to my mother before it did.

I was already near the building where my mother works at. As I was walking, I suddenly felt like there was something above me. I looked up and saw a body of a giant creature. It was dark blue and brown colour. It seemed to have scales. The creature did something like a snake-like movement, but it didn't look like a snake. It's hard to explain.

This lasted for about 5 seconds then I screamed and looked down and started running with tears in my eyes.

I told my parents about this and they said it was my imagination. I believed them, because it was easier to believe it was all in my head than to think of that creature I was so scared of.

I never thought about it for years, but couple of months ago, I was thinking something about my past and I remembered this again. Now I don't believe it was my imagination ...