Klutz

A 'klutz' is a clumsy person who trips a lot and/or drops things.

Example:
-Dad is such a klutz!
-Yeah, he broke Mom's favorite vase!

Bull in a china shop

If someone is a 'bull in a china shop,' it means they are somewhat clumsy -- not very graceful -- and prone to breaking things.

Example:
-I'm sorry for breaking your vase, Mom.
-It's okay. You're a bull in a china shop.