Card

Kha'Zix, Mutating Horror
UNL-143/219 · UnleashedAmbush (You may play me as a Reaction to a battlefield where you have units.)
When I attack or defend, if an enemy unit is alone here, give me +2 this turn and gain 2 XP.
Other printings

Ambush (You may play me as a Reaction to a battlefield where you have units.)
When I attack or defend, if an enemy unit is alone here, give me +2 this turn and gain 2 XP.