Write a short unusual story with (in continuous past and past simple) max 6 lines vamos gente alguien me ayude : c?

The other day i was walking down street, when i saw this huge dog, it was black and it was running side to side playing with a plastic ball.

I got curious so I approached him.

It had big and really white teeth.

When I tried to touch his head, it disappeard, not just the head, but all his body.

I thought I was dreaming, but the ball which the dog was playing still there.

I looked everywhere, but there wasnt any clue where the big black dog had gone.