Runs function constantly?

I'm trying to take all the zombies off when the character dies and resets the level, but instead of spawning 3 zombies for level 1, it spawns an uncountable amount.

Zombie = game.Lighting.Zombie:Clone()
Num_Zom = 0
Level = 1

function Stance()
    repeat local Zom2 = Zombie:Clone()
    local pos = Vector3.new(math.random(-150,150),0,math.random(-150,150))
    Zom2.Parent = workspace
    Zom2:MakeJoints()
    Zom2:MoveTo(pos)
    Num_Zom = Num_Zom + 1
    until Num_Zom == Level * 3
    while wait(3) do
    for i,v in pairs (game.Workspace:GetChildren()) do
    if v.Name == "Zombie" and v.Humanoid.Health == 0 then
    Num_Zom = Num_Zom - 1
    v:remove()
    end
    if Num_Zom == 0 then
    Level = Level + 1
    for i,v in pairs (game.Players:GetPlayers()) do
        v.stats.Level.Value = Level
    end
    Stance ()
    end
    end
    end
end

game.Players.PlayerAdded:connect(function(Player)
    Stance()
end)

game.Players.PlayerAdded:connect(function(Player)
local ting = false
Player.CharacterAdded:connect(function(Char)
if ting == true then
    ting = false
    Stance()
end
Char.Humanoid.Died:connect(function()
    for i,v in pairs (game.Workspace:GetChildren()) do
    if v.Name == "Zombie" then v:remove()
    Level = 1
    end
    end
ting = true
end)
end)
end)

while wait(5) do print (Level) end