This is just a simple mod that randomizes ShadowCaster monsters into Heretic. Each enemy placement in Heretic has been replaced with a randomspawner. There is forty-four or so added monsters in total. I am a big fan of ShadowCaster and the Raven Software style sprites are so visually similar to Heretic that I think they fit. I tried to find other mods that used the sprites and there were only a few here and there and not the entire bestiary. There is also support for Wrath of Cronos or Brutal Heretic RPG as an option.
To run the mod you must load FantasyMonsters.pk3 with GZDoom/Zandronum and select Heretic.
Then you must choose one of the following to also load with it.
FantasyM_SC.pk3 - Shadowcaster & Heretic monsters mix
Wrath of Cronos support:
FantasyM_SC_Woc.pk3 - Shadowcaster & Heretic monsters mix
Brutal Heretic RPG support:
FantasyM_SC_BR.pk3 - Shadowcaster & Heretic monsters mix