https://www.curseforge.com/minecraft/mc-mods/geode

This mod has unfortunately been discontinued so I think rotten creatures might be an ideal home for these zombies.

i know there are already undead miners that drop the same thing, but the concept of an underground zombie that grow ores out of its orifices and drop the matching ores is so good, undead miners can spawn exclusively in mineshafts while these are rare spawn scattered across the deepslate levels.