How do I make an animation trigger when walking?

I'm trying to make a simple walking animation for an NPC. I've looked through many other models in the toolbox and tutorials to see if I could figure it out, but have had no luck.

It's a custom rig (dog) and uses a humanoid part. I was able to make it wander around, but can't start and stop the walking animation when it's needed. The closest I've gotten so far is a constant animation that never stops which is the following script:

local char = script.Parent
local hum = char:WaitForChild("Humanoid")
local animation = hum:LoadAnimation(script.Animation)

animation:Play()

The script for the wandering is the following:

local CurrentPart = nil
local MaxInc = 16


function onTouched(hit)
	if hit.Parent == nil then
		return
	end

	local humanoid = hit.Parent:findFirstChild("Humanoid")

	if humanoid == nil then
		CurrentPart = hit
	end
end

function waitForChild(parent, childName)
	local child = parent:findFirstChild(childName)

	if child then
		return child
	end

		child = parent.ChildAdded:wait()

		if child.Name==childName then
			return child
		end
	end
end

local Figure = script.Parent
local Humanoid = waitForChild(Figure, "Humanoid")
local Torso = waitForChild(Figure, "Torso")
local Left = waitForChild(Figure, "LeftLeg")
local Right = waitForChild(Figure, "RightLeg")

Humanoid.Jump = true

Left.Touched:connect(onTouched)
Right.Touched:connect(onTouched)

while true do
	wait(math.random(2, 6))

	if CurrentPart ~= nil then
		if math.random(1, 2) == 1 then
			Humanoid.Jump = true
		end

		Humanoid:MoveTo(Torso.Position + Vector3.new(math.random(-MaxInc, MaxInc), 0, math.random(-MaxInc, MaxInc)), CurrentPart)
	end
end

If any of you know how to make the walking animation activate for a walking animation, it would be greatly appreciated!