Isekai anime has been dominating the anime landscape for quite some time now, and while the genre often revolves around human protagonists gaining extraordinary powers, there's a fascinating subgenre that flips the script: monster isekai. These anime follow protagonists who are reincarnated or transported into a fantasy world as creatures—beasts, undead, and even slimes. Not only do these anime present unique challenges and opportunities for the characters, but they also explore what it means to be "other," and how even the most unlikely creatures can rise to greatness. Let's take a look at some of the best monster isekai anime and what makes them so captivating.
1. I’m a Spider, So What?
Genres: Action, Comedy, Fantasy, Adventure
One of the most unconventional entries in the monster isekai subgenre, I’m a Spider, So What? (Kumo desu ga, Nani ka?) tells the story of a high school girl who is reincarnated as a spider in a labyrinth-like dungeon. While the premise may sound strange, the anime mixes intense survival action with humor and creative world-building as the spider protagonist grows stronger. Throughout her journey, she faces otherworldly threats, forms unexpected alliances, and uncovers the mysteries of her new reality.
Why watch it? The mix of intense action, clever world-building, and a highly relatable protagonist (even as a spider) is what makes this anime stand out. If you love watching characters evolve and adapt to their circumstances, I’m a Spider, So What? offers an entertaining ride.
2. I’m a Behemoth, An S-Ranked Monster, But Mistaken For A Cat, I Live As An Elf Girl’s Pet
Genres: Comedy, Fantasy, Slice of Life
This light-hearted and whimsical anime follows the story of a man reincarnated as a behemoth monster. But, due to his cute and fluffy appearance he’s mistaken for a cat by an elf girl. While he’s an incredibly powerful S-ranked monster, his disarming appearance leads to comedic situations as he lives as a pet, keeping his true power hidden. The anime strikes a fun balance between light-hearted comedy and fantasy adventure as the behemoth navigates his new, low-stakes life as a pet.
Why watch it? If you’re looking for something fun and easy to watch with lots of humor, this anime will bring plenty of laughs while exploring how even the most fearsome monsters can find peace in an unexpected life.
3. Skeleton Knight in Another World
Genres: Action, Adventure, Fantasy, Isekai
In Skeleton Knight in Another World, a gamer finds himself reincarnated as his in-game avatar: a powerful skeleton knight. While his physical form may be intimidating, his personality is far from monstrous, and he often struggles with being seen as a monster in the world he inhabits. The series balances intense action scenes with moments of self-reflection as the skeleton knight works to navigate his new world and interact with others, despite his appearance.
Why watch it? If you're looking for an anime where the protagonist is a monster struggling with his identity while also being a force of great power, Skeleton Knight offers a compelling mix of action, world-building, and heartfelt moments.
4. That Time I Got Reincarnated as a Slime
Genres: Action, Fantasy, Adventure, Comedy, Magic
One of the most well-known monster isekai anime, That Time I Got Reincarnated as a Slime (Tensei Shitara Slime Datta Ken) follows Satoru Mikami, who is reincarnated as a slime in a fantasy world. While being a slime seems weak at first glance, Rimuru Tempest (the slime's new name) gains the ability to absorb other creatures' powers, gradually transforming into one of the most powerful beings in the world. The anime showcases Rimuru’s journey of leadership, diplomacy, and the creation of a society where monsters and humans can coexist.
Why watch it? This anime is beloved for its optimism, world-building, and compelling protagonist. Rimuru's journey from a humble slime to a powerful leader is inspiring, and the series mixes lighthearted moments with thrilling political drama.
5. Re:Monster
Genres: Action, Adventure, Fantasy, Drama
In Re:Monster, the protagonist is reincarnated as a goblin in a medieval fantasy world after his death. However, unlike typical goblins, he retains his memories and is given the ability to evolve by consuming other monsters. As he builds a group of allies, he rises from being a weak goblin to a mighty force capable of challenging powerful foes. The series delves into themes of survival, personal growth, and leadership in a harsh, monster-filled world.
Why watch it? If you enjoy anime where the protagonist starts out weak but grows stronger through effort and determination, Re:Monster is a great choice. Its focus on the goblin’s evolution and leadership within a monster society makes it a compelling watch for fans of character growth.
6. Overlord
Genres: Action, Dark Fantasy, Supernatural, Isekai
While Overlord doesn’t feature a traditional "monster" protagonist in the usual sense, it’s a defining anime in the monster isekai genre. The story follows Suzuki Satoru, who is reincarnated as his in-game character, the undead overlord of a guild called Ainz Ooal Gown. As the supreme ruler of an army of monstrous beings, Ainz begins exploring his new world, while managing political intrigue and using his terrifying power to expand his influence. The anime leans heavily into themes of power dynamics, morality, and the nature of existence.
Why watch it? Overlord offers a darker, more strategic take on the monster isekai genre. It features a morally complex protagonist who operates in a world full of danger, intrigue, and supernatural beings. Fans of darker fantasy with strong world-building and complex characters will enjoy this anime.