This is a 3D scan model of a human head, which was originally created by Lee Perry-Smith. You can download the Unity package file from here.
All the model and image files in this package are provided under the Creative Commons Attribution 3.0 Unported license.
The original scan data was created by Lee Perry-Smith. Morgan McGuire and Guedis Cardenas converted it to convenient formats. Keijiro Takahashi did some small tweaks to be properly imported into Unity.
Please see the license file for further details.