Here are the answers to the English idioms featuring animals:
To bark up the wrong tree
– choose the wrong way of doing something
To buy a pig in a poke
– buy something without knowing if it will be satisfactory
To be a cash cow
– be a good, and often easy, way to make money
To cry wolf
– warn of a danger that is not there
To be a dark horse
– be a candidate little known to the public
To be an eager beaver
– be a person who is always happy to work or do something extra
To get someone’s goat
– annoy someone
To get on your high horse
– behave with arrogance
To hold your horses
– wait, be patient
To horse around
– play around in a physical way
To be in the doghouse
– be in trouble or disfavor with someone
To let the cat out of the bag
– tell something that is supposed to be a secret
To live high off the hog
– have the best of everything
To look a gift horse in the mouth
– complain if a gift is not perfect
To make a mountain out of a molehill
– make something that is unimportant seem important
To put the cart before the horse
– do things in the wrong order
To smell a rat
– be suspicious or somone or something
To take the bull by the horns
– take decisive action