Killing at random

[ShadowSnipe4]

Is there a way to make it so that a unit gets killed every X seconds withought making that unit part of a variable? Like a kill a random unit in X region every 2 seconds? I want to add this to a castle moat where theres creatures in the water that kill the enemies crossing it.

 

[Rad]

Event: Time - Every X seconds of the game
Action: Unit Group - Pick <Random X units from <Unit in <Region>>> and do - Unit - Kill <Picked Unit>