The answers to the clues below are CAT-related expressions.

1. Blab a secret
2. Metaphor for a downpour
3. Hershey chocolate wafer candy
4. Ante up - as in poker
5. Himalayan capital
6. Speechless
7. Really great, special, cool, etc. (2)
8. Diagonally across an intersection
9. Wildly popular Japanese brand
10. Opthalmologist's assignment, perhaps
11. Raccoon coat wearer in 1928
12. Back-and-forth competition - with "game"
13. Instrument of severe physical punishment
14. Throws a fit
15. Critical task that is extremely difficult to do

Answers:

1. Let the cat out of the bag
2. Raining cats and dogs
3. KitKat bar
4. Feed the kitty
5. Katmandu
6. Cat's got your tongue
7. Cat's pajamas/Cat's meow
8. Kitty-corner
9. Hello Kitty
10. Cataract surgery
11. Cool cat
12. Cat and mouse game
13. Cat o' nine tails
14. Has kittens
15. Belling the cat