Is There a Way to Be Able to Make the R15 Knife *Works* to Only do Damage to NPCs?

I've tried and tried to be able to insert a damage check that makes sure that the knife doesn't do any damage to players but I just can't get it to work. Please help.

Thank you!

(R15 Knife Works script)

local parent = script.Parent
local Handle = parent:WaitForChild("Handle")
local Creator = parent:WaitForChild("Creator")
CanDmg = false
Can = true
parent.Equipped:Connect(function()
	Handle.Equip:Play()
	if Creator.Value == nil then
		Creator.Value = parent.Parent end
end)
parent.Unequipped:Connect(function()
	Handle.UnEquip:Play()
end)
repeat wait() until Creator.Value ~= nil
parent.Activated:Connect(function()
	if Handle.Transparency == 1 then return end
	function slash()
		print("hip")
		local creator = Creator.Value
		local Animations = parent:WaitForChild("Animations")
		local AnimChild = Animations:GetChildren()
		local AnimRad = math.random(1,#AnimChild)
		local AnimSel = AnimChild[AnimRad]
		local AP = creator:WaitForChild("Humanoid"):LoadAnimation(AnimSel)
		if Can == true then
			Can = false
			AP:Play()
			wait(0.15)
			CanDmg = true
			Handle.Swing:Play()
			Handle.SlashTrail.Enabled = true
			wait(0.25)
			CanDmg = false
			Handle.SlashTrail.Enabled = false
			wait(0.06)
			Can = true
		end
	end
	slash()
end)
function on(t)
	local h = t.Parent:FindFirstChildOfClass("Humanoid")
	if h ~= nil and CanDmg == true then
		CanDmg = false
		local cre = Creator.Value
		h:TakeDamage(parent.Dmg.Value)
		Handle.Swing:Stop()
		Handle.Hit:Play()
		if h.Health>0 then
			if not h:FindFirstChild("creator") then
				local ov = Instance.new("ObjectValue",h)
				ov.Name = "creator"
				ov.Value = game.Players:WaitForChild(cre.Name)
			else
				local ovs = h:GetChildren()
				for i = 1,#ovs do
					if (ovs[i].Name == "creator") then
						ovs[i].Value = game.Players:WaitForChild(cre.Name) end
				end
			end
		end
	end
end
Handle.Touched:Connect(on)

Rename the NPC humanoid name to something that cant be confused with the players' humanoid.

Example:

local Knife = game.Workspace.Knife

Knife.Touched:Connect(function(p)
	
	if p.Parent:FindFirstChild("NPCHumanoid") then
		
		p.Parent.NPCHumanoid:TakeDamage(25)
		
	end
	
end)

That way if the knife does touch a player it wont damage the player because the players' humanoid wont be detected.