Not only ferocious and savage wolves are mentioned in the Bible, but other animals as well, namely sheep, snakes and doves. Read about them in Matthew 10:16 ” I am sending you out like sheep among wolves. Therefore be as shrewd as snakes and innocent  as doves.” Also Luke 10:3! Lambs are mentioned in Luke 10:3.

Acts 20:29 says, ” I know that after I leave, savage wolves will come in among you and will not spare the flock.”  Read also Acts 20:30, 31 and notice the tears of the apostle Paul.

And listen now to the words of our Lord and Saviour Jesus Christ: “Watch out for false prophets. They come to you in sheep’s clothing, but inwardly they are ferocious wolves.” Matthew 7:15

The Collins Concise Dictionary says that “a malicious person in a harmless or  benevolent disguise  is a wolf in sheep’s clothing.”