A werewolf is a man who turns into a wolf at night with the full moon and devours people. This type of wolf is a fable, but there is a werewolf in the spiritual realm who targets Christians. This one is real.
Satan and demons are described in the Scriptures as resembling dangerous animals and beasts for their viciousness.
9 And the great dragon was hurled down—that ancient serpent called the devil and Satan, the deceiver of the whole world. He was hurled to the earth, and his angels with him. -Revelation 12:9 BSB
Satan is described as a great [red] dragon (Rev. 12:3) and a serpent, pointing to Genesis 3:1.
1 Then I saw a beast with ten horns and seven heads rising out of the sea. There were ten royal crowns on its horns and blasphemous names on its heads…11 Then I saw another beast rising out of the earth. This beast had two horns like a lamb, but spoke like a dragon. -Revelation 13:1, 11 BSB
The antichrist and his false prophet are described as beasts. In Greek, the word “beast” means a wild animal that’s very dangerous (Gr. Strong’s #2342).
You will tread on the lion and cobra; you will trample the young lion and serpent. -Psalm 91:13 BSB
Behold, I have given you authority to tread on snakes and scorpions, and over all the power of the enemy. Nothing will harm you. -Luke 10:19 BSB
The lion (also mentioned in 1 Peter 5:8), cobra, snakes, and scorpions are all in reference to demons.
Jesus said in Matthew 7:15 that false prophets are wolves who pretend to be Christians, looking for those who are struggling with their faith to devour and destroy them. That is your spiritual biblical werewolf—a man pretending to be a prophet of God on the outside, but on the inside, a destructive wolf.
How can you defeat a spiritual werewolf? By putting on the full armor of God, see Ephesians 6:10-17.
Put on the full armor of God, so that you can make your stand against the devil’s schemes. -Ephesians 6:11 BSB