attempt to index global 'Tool' (a nil value) Can yall give me some help?

Every time i run the script in roblox studio it says attempt to index global "Tool" (a nil value") Can you guys help me Thank you! Heres the script

OUT=false;
SATTACKING=false
SBeast=Instance.new("Part")
SBeast.TopSurface=0
SBeast.BottomSurface=0
SBeast.Anchored=true
SBeast.Name="Ogawa"
SBeast.Size=Vector3.new(3,3,3)
SBeast.BrickColor=BrickColor.new("Really black")
m=Tool.JawMesh:clone()
m.Parent=SBeast
m.Scale=Vector3.new(2,2,2.5)
sbct=0
game:GetService("RunService").Stepped:connect(function()
		local s=SBeast
		if s.Parent~=nil then
			local fow=.6
			local pos1=SBeast.CFrame*CFrame.new(0,0,-fow)
			local pos2=SBeast.CFrame*CFrame.new(0,0,-50)
			SBeast.CFrame=CFrame.new(pos1.p,pos2.p)
			sbct=sbct+1
		if sbct==4 then
			sbct=0
local 	p=Instance.new("Part")
			p.TopSurface=0
			p.BottomSurface=0
			p.CanCollide=false
			p.Anchored=true
			p.BrickColor=BrickColor.new("Really black")
			p.formFactor="Symmetric"
			p.Size=Vector3.new(1,1,1)
			p.CFrame=s.CFrame*CFrame.new(0,0,-1)
			p.Parent=Tool
			local m=Instance.new("BlockMesh")
			m.Parent=p
			m.Scale=Vector3.new(3,3,3)
			coroutine.resume(coroutine.create(function(p) for i=1, 18 do p.Mesh.Scale=p.Mesh.Scale-Vector3.new(3/18,3/18,3/18) p.CFrame=p.CFrame*CFrame.fromEulerAnglesXYZ(math.random(-10,10)/20,math.random(-10,10)/20,math.random(-10,10)/20)+SBeast.CFrame.lookVector*-.2 wait() end p.Parent=nil end),p)
			end
		end
end)