RTF is a global modification that replaces all towns in the game.

Did they finally get rid of the Ghoul from the 6th game? Wouldn't it have been better to make it a Goblin?

The unupgraded creature is a walking dead, created by Lokken.
I like the ghoul-mummy because it turns out to be semi-canonical - in Dark Messiah, Necromancers conducted experiments on the inhabitants of Stonehelm.

These zombies are the result of an experiment on ordinary people. Instead of fast and easily controlled zombies, ordinary zombies were created, but they are weaker and only follow their desire to devour the flesh of the living.

In the game, fast zombies never appeared due to the serial maniac who slaughtered all the undead intellectuals, but it is likely that the experiments could have continued with necromancers from other fortresses - thus, ghoul-zombies will appear - they are faster as planned, but less protected and do not spit poison.