Storm in a Teacup

A lot of commotion or fuss about a trivial matter

Bite the Hand That Feeds You

To act badly toward someone who has helped you

Steal the Show

To attract the most attention and praise at an event

Brain Teaser

A problem or puzzle that is difficult to solve

Out of the Blue

Unexpectedly, without warning

Don't Judge a Book by Its Cover

Do not judge something by its appearance alone