Changing player scale on server?

This has been causing me issues for days, please help! I'm trying to make one random player on the server much bigger than the other players. Here's my script:

local AllPlayers = game.Players:GetPlayers()
local giant = AllPlayers[math.random(1,#AllPlayers)] 
local weapon = game.ReplicatedStorage["GiantClub"]

wait(5)

for i, player in ipairs(game:GetService("Players"):GetPlayers()) do

    if giant.Name == player.Name then
        if player.Backpack:FindFirstChild("GiantClub") == nil then
            local gunclone = weapon:Clone()
            gunclone.Parent = player.Backpack

            player.Character.Humanoid:WaitForChild("BodyDepthScale").Value = 4 
            player.Character.Humanoid:WaitForChild("BodyHeightScale").Value = 4
            player.Character.Humanoid:WaitForChild("BodyWidthScale").Value = 4
            player.Character.Humanoid:WaitForChild("HeadScale").Value = 4
        end
    end
end

It works locally, but on the server nothing happens. I'm running the script as a regular script in a folder in ReplicatedStorage.