Answer:
What has 3 feet but no toes?
Forward I am heavy backward I am not. What am I?
As I went over London Bridge I met my sister Jenny; I broke her neck and drank her blood and left her standing empty.
What type of house weighs the least?
I am heavy forward, but backward I'm not. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.