So usually you would stop an animation like so:
local Animation = Instance.new("Animation")
Animation.AnimationId = "http://www.roblox.com/Asset?ID=SomeID"
local AnimTrack = Char.Humanoid:LoadAnimation(Animation)
AnimTrack:Play()
wait(1)
AnimTrack:Stop()
But how would you stop the Animation without access to the AnimTrack?