My first thought (even though it's a bit of an overused meme) is that these look exactly like the holes in Japanese horror manga master Junji Ito's /The Enigma

My first thought (even though it's a bit of an overused meme) is that these look exactly like the holes in Japanese horror manga master Junji Ito's /The Enigma of Amigara Fault/ (don't look that up if you're claustrophobic or not cool with body horror).