  The Tail of a Pig is imbued with it's fear.
<~><~>  This emotion can be brewed into a Terror potion; under this effect, creatures become irrationally afraid of every other creature around them for 1 minute.
<~><~>  This effect draws its magic from Infernality in the School of Illusion.
<~><~>  Terror can also be achieved in a Brewing Stand by corrupting an Infatuation potion with a Fermented Spider Eye.