They’re called “Void Gatos”
They can be found on almost any level (besides the devoid levels), they are fairly hostile creatures, and they will try and attack any wanderer nearby
They kill wanderers like puncturing them with their ribcage, then they’ll drag the body away into the darkness or any hole near them, they’ll even kill other entities if possible (if they are hostile)
They also seem to be “companions” for partygoers and smilers at times