Carl's class spell that frightens mobs into fleeing or drops their dexterity — useless on 'scary' foes.
Fear is the spell Carl gained with his Compensated-Anarchist class (costing 3 points). A successful cast either makes a mob flee or, if it stands, lowers its dexterity by an amount that grows each skill level; at level 5 it affects groups. All the Grimaldi's Traveling Circus monsters were immune ('scary-ass mobs are immune from Fear'), but ordinary Over City mobs are not.
Mordecai urged Carl to cast it every fight; the catch is that frightened mobs run off, denying experience unless killed — which is why it opens the party's 'Panic' play (Fear, then Donut's Magic Missile). Carl trained it to level 3 on the trek.
Carl's crowd-control debuff and the opener of the party's first play.