A downloadable mod

Requires GZDoom 3.0 or later.

What's the Green Demon Challenge? Here's its origin:

Once you start moving, the Green Demon appears at your start spot and will track you relentlessly, passing through walls and scaling any height. Its touch means C̮̦͘É̺̯̲̼̮̞R͘T̫̣̰ͅA̻̤͎͞Ì͕͕̩͔̦N͏̹̟̬̩ ̨D͖̯̰͕E̢͚A̷͔͉T̫̺̝͖̻H̩͎̦̟̫̥ͅ to you and any monsters that get in its way.

Positional audio on the Demon itself helps you locate it. Headphones recommended!

To make things a bit more interesting, I've added a damage bonus (you deal more to monsters) and resistance (monsters deal less to you) when the Green Demon is within two different ranges of you. So while letting it touch you is bad, letting it get close makes you a terror to all nearby monsters.

Check the options menu for a few customization features:

  • Green Demon's speed: The default is reasonable on most levels, crank it up for a truly terrifying challenge, or crank it down if a level just isn't  possible at the default.
  • Spawn delay: After you move from your starting spot, you'll have this many seconds of head start before the Green Demon appears.
  • Demon proximity bonuses: You can disable the abovementioned bonuses if you feel they detract from your experience.
  • Invulnerability powerup survives: When this is off, the Green Demon will still kill you even if you have an invulnerability powerup active!
  • Demon appearance: Use this to change what the Green Demon looks like.


green-demon-doom-mod.zip 634 kB
Version 5 May 31, 2020

Install instructions

Open the file "greendemon.zip" or its enclosed "greendemon.pk3" with GZDoom, either from the command line or by dragging the mod onto GZDoom's icon.

Development log


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Would it be possible to make this Zandronum compatible?

I really love this mod.  Helps add to the the setup I have going for DoomRPG launcher.

So far my feedback is:

  • Most importantly can you add a spawn distance for the greendemon. Spawns way to close in all the maps I've tested so far.
  • Please add the ability to load PNG files as the greendemon from a folder if possible. This would be great for replay value.
  • More effects
    • Heals monsters
    • Resurrects monsters
    • Area of effect
    • Sets entities on fire

Hope to see more from you, this is genius. 

Did the first item: https://jp.itch.io/green-demon-doom/devlog/150801/new-build-spawn-distance-is-no...

As far as customizing the appearance of the Green Demon, you can create an additional mod PK3 that loads in on top of this one. All you'd need to do is replace one of the PNG files in the sprites/ subdirectory.

This is a cool idea!