Answer:
What do you get when you cross a pig with a karate expert?
I am the building with the most number of stories.
I have thirteen hearts but no body or soul.
I run around the city but I never move.
I am a busy worker who is a water mammal.
No matter how little or how much you use me, you change me every month.
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic