Because Iron melts thimble and flattens dog.
Only the car can destroy the iron. (The battleship could try, but I doubt they could find the iron.)But now, since it's a cat. Do the cat and dog fight? What can a cat do against a thimble? A Battleship? A wheelbarrow?
Why do I get the feeling this change was initiated by a catfancy group?
And why above all things did the ROBOT not win?
Seems like an easy choice when compared to a helicopter, a guitar or a ring.