attempt to index nil with 'Character'?

Another day, another scripting error... I've been touching up a script for the past few days. It's supposed to weld a part onto the player that touches a hazard. This, of course, has resulted in a lot of bugs with the script. This time, the char (Character) variable doesn't want to work. whenever I step on the hazard, it plays the correct animation through the player's humanoid, but it doesn't changed the walkspeed to 0 nor does it go through with the welding functions. I am at my wit's end trying to fix this and just about to give up. Can you guys help me?

Local script (In StarterCharacter)

local puddle = game.Workspace.GooClusterMPE.Puddle
puddle.Touched:Connect(function(touch)
	local plr = game.Players:GetPlayerFromCharacter(touch.Parent)
	local char = plr.Character or plr.CharacterAdded:wait()
	if plr.Team == game.Teams.Humans then
		local animation = game.Workspace.Anims.Animation
		local animtrack = char.Humanoid:LoadAnimation(animation)
		local sound = game.Workspace.Sound
		char.Humanoid.WalkSpeed = 0
		game.Players.LocalPlayer.Team = game.Teams.Infected
		animtrack:Play()
		local repStore = game:GetService("ReplicatedStorage")
		local Human = touch.Parent
		local sound = game.Workspace.Sound
		sound:Play()
		--repStore.Transfurs.MPEGoo:FireServer(plr,char)
		char.Humanoid.WalkSpeed = 16
	end
end)
game.Players.LocalPlayer.Character.Humanoid.Died:Connect(function(touch)
	local plr = game.Players:GetPlayerFromCharacter(touch.Parent)
	plr.Team = game.Teams.Humans
end)

Server Script (In ServerScriptService)

game.ReplicatedStorage.Transfurs.MPEGoo.OnServerEvent:Connect(function(plr,char)
	local messyArmL = game.ServerStorage.MessyLimb:Clone()
	local messyArmR = game.ServerStorage.MessyLimb:Clone()
	local messyLegL = game.ServerStorage.MessyLimb:Clone()
	local messyLegR = game.ServerStorage.MessyLimb:Clone()
	local messyTorso = game.ServerStorage.MessyTorso:Clone()
	local ArmL = char["Left Arm"]
	local ArmR = char["Right Arm"]
	local LegL = char["Left Leg"]
	local LegR = char["Right Leg"]
	local Torso = char["Torso"]
	
	--Left Arm
	local weldAL = Instance.new("WeldConstraint")
	weldAL.Part0 = ArmL
	weldAL.Part1 = messyArmL
	weldAL.Parent = ArmL
	messyArmL.Position = ArmL.Position
	messyArmL.Orientation = ArmL.Orientation
	messyArmL.Parent = game.Workspace
	messyArmL.Color = Color3.new(1, 1, 1)
	--Right Arm
	local weldRA = Instance.new("WeldConstraint")
	weldRA.Part0 = ArmR
	weldRA.Part1 = messyArmR
	weldRA.Parent = ArmR
	messyArmR.Position = ArmR.Position
	messyArmR.Orientation = ArmR.Orientation
	messyArmR.Parent = game.Workspace
	messyArmR.Color = Color3.new(1, 1, 1)
	--Left Leg
	local weldLL = Instance.new("WeldConstraint")
	weldLL.Part0 = LegL
	weldLL.Part1 = messyLegL
	weldLL.Parent = LegL
	messyLegL.Position = LegL.Position
	messyLegL.Orientation = LegL.Orientation
	messyLegL.Parent = game.Workspace
	messyLegL.Color = Color3.new(1, 1, 1)
	--Right Arm
	local weldRL = Instance.new("WeldConstraint")
	weldRL.Part0 = LegR
	weldRL.Part1 = messyLegR
	weldRL.Parent = LegR
	messyLegR.Position = LegR.Position
	messyLegR.Orientation = LegR.Orientation
	messyLegR.Parent = game.Workspace
	messyLegR.Color = Color3.new(1, 1, 1)
	--Torso
	local weldT = Instance.new("WeldConstraint")
	weldT.Part0 = Torso
	weldT.Part1 = messyTorso
	weldT.Parent = Torso
	messyTorso.Position = Torso.Position
	messyTorso.Orientation = Torso.Orientation
	messyTorso.Parent = game.Workspace
	messyTorso.Color = Color3.new(1, 1, 1)
	--Head
	local NewHead = game.ServerStorage.massproducedgoo:Clone()
	local OldHead = char.Head
	local headweld = Instance.new("Weld")
	headweld.Parent = game.Workspace
	headweld.Part0 = OldHead
	headweld.Part1 = NewHead.Headroot
	NewHead:MoveTo(OldHead.Position)
	NewHead.Parent = game.Workspace
	OldHead.Color = Color3.new(1, 1, 1)
	
	messyLegL.Transparency = 1
	messyLegR.Transparency = 1
	messyTorso.Transparency = 1
	messyArmL.Transparency = 1
	messyArmR.Transparency = 1
	wait(0.25)
	messyLegL.Transparency = 0.75
	messyLegR.Transparency = 0.75
	wait(0.25)
	messyLegL.Transparency = 0.5
	messyLegR.Transparency = 0.5
	wait(0.25)
	messyLegL.Transparency = 0.25
	messyLegR.Transparency = 0.25
	wait(0.25)
	messyLegL.Transparency = 0
	messyLegR.Transparency = 0
	wait(0.1)
	messyArmL.Transparency = 0.75
	messyArmR.Transparency = 0.75
	wait(0.25)
	messyArmR.Transparency = 0.5
	messyArmL.Transparency = 0.5
	wait(0.25)
	messyArmR.Transparency = 0.25
	messyArmL.Transparency = 0.25
	wait(0.25)
	messyArmR.Transparency = 0
	messyArmL.Transparency = 0
	messyTorso.Transparency = 1
	wait(0.1)
	messyTorso.Transparency = 0.75
	wait(0.25)
	messyTorso.Transparency = 0.5
	wait(0.25)
	messyTorso.Transparency = 0.25
	wait(0.25)
	messyTorso.Transparency = 0
end)