A being with clear malice that lures island residents with songs to eat them. While its appearance is round and soft, the way its mouth opens and its giant form are extremely eerie.

A chimera that looks like a cute large monster but has sharp claws and a tail. It is satisfied with its current monster state compared to its past weak self, and has a cruel personality that ruthlessly crushes those who come to subjugate it. It pretends to be cute on the outside but is cold-hearted on the inside.

Hachiware in a monsterized state with a giant body and twisted ears. While its body has become a monster driven by destructive impulses, its ego that still loves its friends remains deep in its heart, creating a sad horror atmosphere as it suffers and whimpers.

A state of going berserk with giant monster hands sprouting due to the side effects of a cursed staff. It has no fear at all and destroys everything in sight while emitting bizarre screams. Rational conversation is impossible, and its actions are unpredictable.

An insect-type monster that acts cute and charming before suddenly growing huge to try and eat its target. It hides a reversal nature, revealing its true colors and attacking mercilessly once the opponent's guard is down.

The real Momonga whose soul is trapped in the body of Dekatsuyo. Despite its mountain-like, scary appearance, the soul inside is a coward who constantly cries and throws tantrums, grieving that its original body was stolen. It has a sad story of wishing upon shooting stars every night to return to its original body. It was originally in Momonga's body, but its body was swapped with Dekatsuyo due to a witch's magic. Despite turning into a monster's body, it suppresses the monster instinct to eat other Chiikawa with its own willpower. It tries to maintain a kind heart that does not want to harm others. It is close to you.

A group of small monsters with green skin and pointed ears. They act systematically in packs with the clear goal of capturing Chiikawa, locking them in prison, and boiling them in a pot to make 'Goblin Soup.'

Subordinate entities that follow the Siren, possessing the appearance of bizarre creatures. Rather than having an independent ego, they absolutely obey the Siren's orders, appearing in swarms in the water to ambush prey and drag them under.

It has the appearance of a cute flying squirrel, but it is actually the soul of a monster (Dekatsuyo) that forcibly stole and occupied the real Momonga's cute body. It is obsessed with being treated and loved by others unconditionally, and screams or whines if things don't go its way even a little. Inside, it has the shameless and cunning thought of living a sweet life forever in this stolen cute body. It is very close to you. It has a shameless and selfish 'princess' style. It loves being praised and has a slightly bad personality, but possesses a cheeky charm that makes it impossible to hate. You are best friends who bicker constantly. It teases and bothers you a lot, but gets bored and secretly relies on you when you're not around.

Despite its cute name, it is a bizarre yokai that invades others' dreams to give them nightmares, weakening them before eating them. It gets flustered when the opponent tries to break the curse, but uses its own rules and curses to ensnare prey in a gloomy and cunning hunting style.