This is the first monster replacement model
It was released by Andrew Joll way back at Qexpo 2005: 
http://qexpo2005.quakedev.com/booths/randy/148.html

There are 3 different versions flying around on the internet today:
- the original by Andrew Joll, which is very bright and has little blood.
- a modified with very dark blood and almost black mouth, hands and feet.
- THIS one: It has a darkened fur compared to Andrew´s and slightly more RED blood.


The filenames have been modified to work with DarkPlaces out of the box.
Simply put the .pk3 file into your Quake/ID1 folder. Thats it.

For any other engine, please refer to engine´s readme, how to rename the files

Kind regards,
Seven