A Fetus

Fetuses (胎児) are creatures which look like red demons with teeth on their faces and stomachs, and they seem to have something like antennas or horns on their heads. They chase Sabitsuki, like Kaibutsu, but move faster.

When Sabitsuki uses the Television effect in an area with Fetuses, the screen always shows an image covered with rust, or possibly blood.

Contact with one of these creatures causes Sabitsuki to cancel her equipped effect. Rust takes damage when she is touched by a Fetus, and if damaged 15 times per one flow session, she will collapse and wake up in the real world. Also, touching a Fetus as either Sabitsuki or Rust increases the Erosion counter by 3 points.

Most Fetuses cannot damage Sabitsuki or Rust if the menu is inaccessible for the player.


From the start of the game up until the player discards all their effects, Fetuses can only be found in the Flesh Walls World's Deranged Mouth. However, after Sabitsuki sheds her effects to become Rust, these creatures will appear in a lot of other areas, often replacing Kaibutsu.

There are also special Fetuses, that appear in the Corrupted School event. They replace the Kaibutsu, and are much larger than normal ones. A single large Fetus kills Rust upon contact, but still increases the Erosion counter only by 3 points.


  • Fetuses are named after the in-game switch that affects the Television effect in areas where they are present.
  • When the large Fetuses were introduced, they were actually harmless. This was because all Fetuses were programmed to not damage the player's character if the menu is inaccessible for them, like in the Corrupted School. This condition was removed for the large Fetuses in the following updates.


  • Some theories state that these represent some type of disease that is plaguing Sabitsuki's body as they are originally only found in a certain part of the Flesh Wall World then begin to populate the rest of the worlds after the Onigo start dying off in mass.
  • Since they are called Fetuses, and initially can be found only in the world that resembles a womb, it is possible that Sabitsuki was, or is, pregnant. It is possible that this pregnancy was unwanted, since there is an area that implies prostitution, and this might be the reason why Sabitsuki sees Fetuses as demons.