The first step to adding in an enemy is to import the assets required to use it. Inside our Chapter 6\Assets\Ghost Model location, you'll find a series of files.

First, let's create the material for our new mesh. To do this, go into either the 1024 Textures or 2048 Textures folder, and move the files into the Materials folder. Afterwards, navigate to Create | Material, and give it the name GhostMaterial. Change the Shader value to Bumped Diffuse, and move the Ghost_Tex file into the Base and Ghost_TEX_NRM file in the Normalmap selection. You'll get a warning indicating the texture isn't marked as a normal map; feel free to click on Fix Now, or go back into the file, and change its Texture Type value to Normal map. The following screenshot shows the Unity screen with these changes:

Now, move to the Models folder on the Project tab, and drag-and-drop the Ghost_mesh...