Very specific fix that aims the FlansGames fork that would make mobs spawns with modded helmets in offhand, and we don't want that. There would be Marine Helmets, Spetsnaz Helmets, Cloakers Helmets and so on (there's a lot in Flan's Mod.)
I made this for my modpack, but just use it if you need it too. No permissions needed.
Only for 1.12.2 because of my modpack. Don't plan to do others versions, sorry.

