He's very mysterious. He's a dark _____, isn't he? (someone with a a secret ability, skill or achievement) (HORSE / BAT)

I'll never get home, traffic is moving at a ___'s pace. (to move very slowly) (FOX / SNAIL)

Why are you silent? ____ got your tongue? (used when a person won't speak) (CAT / DOG)

Don't start trouble, you don't want to open a can of ___s. (to make a situation worse) (WORMS / MICE)

You can do this! It's time to take the ___ by the horns! (to face a challenge) (BULL / FROG)

I'd love to be a _____ on the wall when she breaks up with him! (to be able to see what people are doing without them noticing you) (FLY / RHINO)

I feel like a _____ out of water. (to be in a situation that you know nothing about or are not used to) (DOG / FISH)

I just woke up and decided to quit smoking cold ___! (to stop something suddenly and completely) (LEOPARD / TURKEY)

I've so many things to do. I'm running around like a headless _____! (trying to do a lot of things quickly without being calm) (FISH / CHICKEN)

Bob's brothers love football but he hates it. He's the black ___ of the family. (to be different to everyone else) (SHEEP / LION)

You're eating so much! You're making such a _____ of yourself. (to eat a lot of food) (COW / PIG)

I have ____s in my stomach. (to be nervous or scared) (SNAKES / BUTTERFLIES)