'Wolves' in the Bible

Beware of false prophets, who come to you in sheep's clothing, but inwardly are ravening wolves.

Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves.

Go your ways; behold, I send you forth as lambs in the midst of wolves.

I know that after my departing grievous wolves shall enter in among you, not sparing the flock;