How would you go about to load an animation on an NPC?

I have an animation that I made and I would like to load it on an NPC to see it now with the Roblox Block character I rigged the gun that I made with it with the plugin Custom Character creator

I loaded animations previuslly with this code

local hum = script.Parent.Humanoid

local anim = hum:LoadAnimation(script.Parent.Animation)

local Aim = script.Parent.Head.Aiming

while true do

    anim:Play()

wait (4)
end

I'm thinking that animation is strictly on the character itself with that script because it wont play with the other animation that involve the gun with it.

How would you go about to load it on an NPC?