Wolf in sheep’s clothing

This expression from the New Testament is commonly used to describe someone who is not all that they seem, or who has an ulterior motive usually to the detriment of others. The source is the New Testament, Matthew 7:15.”Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves.” It is alleged that Winston Churchill once referred to Clement Atlee as ‘a sheep in sheep’s clothing’ but the authenticity of this has been questioned.