There is some nudity, but nothing very explicit is shown.

In one episode, Maria-sama mentions Utsutsu's semen and Yume's egg cells, planning to give birth to a monster child.

A man makes a brief joke to Maria-sama about fondling her breasts.

This anime is very gory, if not one of the goriest anime TV-series having been made in Japan.

The scene where Utsutsu's little sister Yume transforms into a monster is very bloody. Yume's body parts are clearly shown.

It is one of the few anime series in which flesh and organs are being eaten by a human character.

A monster bursts out from a dog.

Some flashback sequences show how a father appeared as being abusive towards his son and daughter. A scene telling the viewer the details about it are made using stuffed teddy bears.

A flashback sequence shows a monster baby covered in blood. The same baby eats a bird.

A bug is cut. We don't see the cutting itself, but we see some green slime on a hospital knife.

After multiple beating and some stabbing, a boy attempts to cut out an another boy's eyeballs, but gets interrupted by a girl.

A boy is tortured, but nearly all of it is implied as we mostly hear his screams.

Many people lay in a great pool of blood, some of them are cut in half.

Smoking occurs about three times overall in this anime.

"Pupa" is one of the most disturbing and goriest anime series having been made in Japan. People sensitive to stuff like family violence, cannibalism and massive gore may not want to watch this.