Touch Event to play an Animation with an NPC?

Yeah, Sure, This should work:

local SP = script.Parent -- The Part To Be Stepped On
local Dummy = workspace.Dummy -- Change "Dummy" To Whatever You Want To Animate, Note* This Only Works Assuming That Your Only Animating One NPC
local Animation = Instance.new("Animation")
local Debounce = true -- Spam Detector
local LD = function(Parent, ID) Animation.Parent = Parent Animation.AnimationId = ID Dummy.Humanoid:LoadAnimation(Animation) end -- Loading Animation For Humanoid

SP.Touched:Connect(function(hit) -- "hit" Is The Part In Question. With This We Can Access The Player Who Stepped On The Block.
    local Hit = hit.Parent
    local AP = Dummy

        wait(.5)

    if Dummy:WaitForChild(Animation, 3) then -- Make Sure That There Is No Animation In Dummy
        print("Animation Found In: "..AP.Name.."..Deleting..")
        Animation:Destroy() -- Disonnecting Left Over Thread
    else
        print("No Animation Found In: "..AP.Name)   
    end

    if Hit:WaitForChild("Humanoid", 3) and Debounce then
        print("Found Humanoid From: "..Hit.Name.."!")
        Debounce = false
        LD(Dummy, "rbxassetid://AnimID") -- "AnimID" Change To Your Animation ID
        wait(.5) -- Can Change Time For Debounce Reset
        Debounce = true
    else
        print("Couldn't Find Humanoid From: "..Hit.Name.."....Or Debounce Is False")
    end
end)

https://gyazo.com/303b1a1f4be62aef223908530f1fe23c -- Where You Should Put The Script

A Bit Over - Complicated But, this should be smooth.

Hope This Helped!

~Farsalis