Using reverse image search technology, I've located the origin of this variant, it comes from a SNCA fangame of yume nikki called yume 2kki and blah blah blah snca. You can find the image of the event on the 'ki for 2kki. Funnilly enough, the map that the jumpscare comes from is called "GEMstone cave", despite the fact that it's coal. https://yume.wiki/2kki/Gemstone_Cave