This mod multiplies most enemies in the game fairly by X5, X7 or X10, without abuse. Compatible with the Randomizer mod.
The flaw of this mod is that if you kill all the zombies in a room, there will be only two zombies left that will turn into Crimson Head. I tried to fix this, but unfortunately I couldn't find a solution to increase the number of corpses in this game.
Warning:
you should not launch the mod with a finished save game.
Launch directly a new blank game, preferably in difficult.