This item is found only in the console version(s) of Terraria.
The Pet Werewolf is one of the console exclusive pets and is summoned using the Wolf Fang. It is a recolored version of the Werewolf and follows the player until it is called off or the player dies. The Werewolf is very aggressive and does damage to enemies on touch (about 10-20 damage). Also, the Wolf Fang can only be found in Hardmode, after the Wall of Flesh has been defeated. On the Mobile version, the Wolf Fang can be found from defeating werewolves.