Add a Humanoid by inserting one into the character model, then make sure the model has the parts Roblox expects, especially a HumanoidRootPart and a Head if RequiresNeck is enabled. In older 2007-era setups, people also used Player:LoadCharacter() or Character.Humanoid-based scripts to work with the humanoid after the character spawned.

Simple setup

For a custom character or NPC, the basic idea is:

  1. Put the model in Workspace or create it in code.
  2. Insert a Humanoid into the model.
  3. Add a HumanoidRootPart.
  4. Connect the body with joints or Motor6Ds.
  5. If needed, add an Animator for animation support.

2007 client style

A 2007 Roblox client is very different from modern Roblox, so the safest old- style pattern is to create a player, load the character, and then access the humanoid through the character, like game.Players.LocalPlayer:LoadCharacter() and then game.Players.LocalPlayer.Character.Humanoid. If you are making a bot or NPC, older community examples show creating a player instance and then using Character.Humanoid:MoveTo(...) to control it.

Minimal example

lua

local model = Instance.new("Model")
model.Parent = workspace

local humanoid = Instance.new("Humanoid")
humanoid.Parent = model

local root = Instance.new("Part")
root.Name = "HumanoidRootPart"
root.Parent = model

That is the core idea, but for it to behave like a real character, the body still needs proper rigging and connections rather than just the Humanoid object alone.

Important note

If your goal is to make the character actually move and animate, the Humanoid is only part of it; the model also needs a valid root part and joints connecting the body together. Modern docs describe a Humanoid as the object that gives models character functionality.

TL;DR

In a 2007 Roblox client, add a Humanoid inside the model, give it a HumanoidRootPart, and use the character reference after loading it; for NPCs, old scripts commonly used Character.Humanoid for movement.