local Players = game:GetService("Players");
local ServerStorage = game:GetService("ServerStorage");
local Player = Players.PlayerAdded:Wait();
local Character = Player.CharacterAdded:Wait()
local ID = --// your target user id goes here
if Player.UserId == ID then
local Trail = ServerStorage:WaitForChild("Trail")
local Attachment0 = Instance.new("Attachment")
Attachment0.Parent = Character.Head
local Attachment1 = Instance.new("Attachment")
Attachment0.Parent = Character.HumanoidRootPart
trail.Attachment0 = Attachment0
trail.Attachment1 = Attachment1
end
The only reason I didn’t use the second optional argument in the Instance.new constructor is because if this is firing regularly (assuming your servers are 100 players in size) then it can get really slow. Reference.