THE SPOT

It was just a plain old day. Me and my friend's were at the park and we found a weird spot it was on a rock we were thinking why a spot is on a rock. but in a while suddenly the spot grew bigger than a tree. Then I just had a really bad thought if the spot don't stop growing it will be bigger than the whole planet. Suddenly we found out the spot was a robot trying to destroy the whole planet but we stopped it. But who had made it in the first place?