NPC Characters not spawning correctly?

I am creating an RPG (RolePlayGame) and have run into a problem.

npc = script.Parent:Clone()

function Died()
	wait(5)
	npc.Parent = script.Parent.Parent
	npc:MakeJoints()
	npc.Enemy.Health = npc.Enemy.MaxHealth
	script.Parent:Remove()
end

script.Parent.Enemy.Died:connect(Died)

Sometimes the npc will respawn, sometimes it won't ever respawn again. I get this error message.

16:44:35.337 - Workspace.Weak Bandit..Respawn:5: attempt to index global 'npc3' (a nil value)
16:44:35.339 - Stack Begin
16:44:35.341 - Script 'Workspace.Weak Bandit..Respawn', Line 5
16:44:35.343 - Stack End

Anyone know what is wrong?

Make sure to add a humanoid in the Enemy. The Died event only works in the humanoid.

npc = script.Parent:Clone()

function Died()
    wait(5)
    npc.Parent = script.Parent.Parent
    npc:MakeJoints()
    npc.Enemy.Health = npc.Enemy.MaxHealth
    script.Parent:Remove()
end

script.Parent.Enemy.Humanoid.Died:connect(Died) --Here is where I added 'Humanoid'