# I'm a Behemoth
**I'm a Behemoth**, also known by the nickname **Beheneko**, a portmanteau of "Behemoth" and "neko", the Japanese word for cat, is a Japanese web novel serialized on [Shōsetsuka ni Narō](https://www.edgepedia.org/shosetsuka-ni-naro) from August 19, 2017 and also posted on Kakuyomu, where it ran to 217 chapters and 557,215 characters as of its July 22, 2025 update.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) • [2](https://kakuyomu.jp/works/1177354054884828035) The story follows a knight who is reborn as a baby behemoth, a monster ranked S, and is taken in as a pet named Tama by the elf adventurer Aria.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) A manga adaptation began with its first collected volume on sale October 29, 2018, and an anime adaptation was announced in March 2024.[6](https://www.hakusensha.co.jp/comicslist/52766/) • [9](https://news.denfaminicogamer.jp/news/240318w) The anime, produced by Zero-G and Saber Works, ran for 12 episodes from January 4 to March 22, 2025, and streamed on HIDIVE as a Winter 2025 simulcast with an English dub.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) • [10](https://blog.syosetu.com/article/view/article_id/4799/) • [3](https://www.fandompost.com/2024/12/28/beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-episode-01-anime-review/) • [1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/)
| Key fact | Detail |
|---|---|
| Original web novel | Serialized on Shōsetsuka ni Narō from August 19, 2017; also posted on Kakuyomu, where it ran to 217 chapters and 557,215 characters as of its July 22, 2025 update[2](https://kakuyomu.jp/works/1177354054884828035) |
| English streaming | Simulcast on HIDIVE as part of the Winter 2025 season, with an English dub[3](https://www.fandompost.com/2024/12/28/beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-episode-01-anime-review/) • [1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) |
| Theme songs | Opening "Supreme Heart" by Nonoka Ōbuchi; ending "Rimi" by Poka Poka Ion, a unit of voice actresses Nao Tōyama and Kiyono Yasuno[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) |
## Premise
The story follows an unnamed knight who dies in battle against the forces of evil and is reborn as a baby behemoth, a monster ranked S, the highest class in the setting. In his infant form he looks like an ordinary small kitten, and he is rescued by Aria, a beautiful elf adventurer with a fondness for elemental cats, who takes him in as her pet and names him Tama.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) Tama retains his knightly honor and pledges to protect Aria, fighting monsters with skills such as attribute-infused attacks while concealing his true nature.[4](https://kakuyomu.jp/works/1177354054884828035/episodes/1177354054884873958) The Kakuyomu synopsis notes that neither Aria nor those around her realize that Tama is a former human reincarnator and the young form of a behemoth rather than a cat.[2](https://kakuyomu.jp/works/1177354054884828035)
The series is an ecchi work, with frequent nudity and bath scenes, and reviewers describe it as a fanservice-first fantasy comedy alongside its adventure plot.[5](https://yoshianimereviews.wordpress.com/2025/03/15/beheneko-the-elf-girls-cat-is-secretly-an-s-rank-monster/) • [3](https://www.fandompost.com/2024/12/28/beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-episode-01-anime-review/) The web novel carries content tags for cruelty, violence, and sexual description.[2](https://kakuyomu.jp/works/1177354054884828035)
## Publication history
**Manga.** The first collected volume went on sale October 29, 2018.[6](https://www.hakusensha.co.jp/comicslist/52766/) The manga became the most prominent version of the property: the anime's official site lists comic volumes 1 through 11 as on sale, and Hakusensha's author catalog shows later volumes continuing the series.[7](https://behemoth-anime.com/books/index.html) • [8](https://www.hakusensha.co.jp/?_searchtype=authors&s=%E9%8A%80%E7%BF%BC%E3%81%AE%E3%81%9E%E3%81%BF) The web novel itself remains ongoing on Kakuyomu.[2](https://kakuyomu.jp/works/1177354054884828035)
## Anime adaptation
An anime adaptation was announced in March 2024.[9](https://news.denfaminicogamer.jp/news/240318w) The series was produced by Zero-G and Saber Works, directed by Tetsuo Hirakawa, with series scripts by Kanichi Katō, character designs by Tomoyuki Abe, and music by Yūsuke Shirato and Oni.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) It ran for 12 episodes from January 4 to March 22, 2025 on [Tokyo MX](https://www.edgepedia.org/tokyo-mx), Sun TV, BS11, and other stations, with an uncensored broadcast on AT-X. The Shōsetsuka ni Narō announcement lists the broadcast schedule: Tokyo MX and Sun TV from January 4, 2025, BS11 from January 5, and the uncensored version on AT-X from January 7, with streaming on ABEMA beginning December 28, 2024.[10](https://blog.syosetu.com/article/view/article_id/4799/) The opening theme, "Saijōkyū no Kokoro" ("Supreme Heart"), was performed by Nonoka Ōbuchi, and the ending theme, "Rimi", by Poka Poka Ion, a music unit formed of voice actresses [Nao Tōyama](https://www.edgepedia.org/nao-toyama) and Kiyono Yasuno.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) • [11](https://aeschtunes.com/2025/02/27/song-review-nonoka-obuchi-saijokyu-no-kokoro/)
**English release.** The series streamed on HIDIVE as a Winter 2025 simulcast, and HIDIVE also produced an English dub.[3](https://www.fandompost.com/2024/12/28/beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-episode-01-anime-review/) • [1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/)
## Reception
Critical response to the anime was divided along the same line as its content. The Fandom Post's review of the first episode gave it a B+, praising the animation and the frank embrace of the show's sexuality.[3](https://www.fandompost.com/2024/12/28/beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-episode-01-anime-review/) Bubbleblabber's English dub season review scored it 7/10, calling it an enjoyable but standard fantasy/ecchi anime with strong voice performances and playful character designs, while noting that its reliance on ecchi tropes may put off some viewers.[1](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/) Yoshi Anime Reviews gave the series 3/10, criticizing the frequent bath scenes, the treatment of its fanservice, and what it saw as weak plotting and uneven animation in the middle episodes.[5](https://yoshianimereviews.wordpress.com/2025/03/15/beheneko-the-elf-girls-cat-is-secretly-an-s-rank-monster/) Japan Powered described the animation as poor in its action scenes while frames concentrated on breast physics, and recommended it only to ecchi fans as a light watch.[12](https://www.japanpowered.com/anime-articles/beheneko) On the tracking site MyShows, users rated the series 3.784 out of 10 as of August 2026, with the second episode, "The Tiger-Eared Blacksmith and a New Skill", the highest rated at 3.97.[13](https://en.myshows.me/view/91890/rating/)
## References
1. [English Dub Season Review: Beheneko Season One, Bubbleblabber (David King, July 2, 2025)](https://www.bubbleblabber.com/2025/07/english-dub-season-review-beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-season-one/)
2. [Ｓランクモンスターの《ベヒーモス》だけど、猫と間違われてエルフ娘の騎士（ペット）として暮らしてます, Kakuyomu](https://kakuyomu.jp/works/1177354054884828035)
3. [Beheneko: The Elf-Girl's Cat is Secretly an S-Ranked Monster! Episode #01 Anime Review, The Fandom Post (Chris Beveridge, December 28, 2024)](https://www.fandompost.com/2024/12/28/beheneko-the-elf-girls-cat-is-secretly-an-s-ranked-monster-episode-01-anime-review/)
4. [第6話 魔牛, Kakuyomu](https://kakuyomu.jp/works/1177354054884828035/episodes/1177354054884873958)
5. [Beheneko: The Elf-Girl's Cat is Secretly an S-Rank Monster!, Yoshi Anime Reviews (March 15, 2025)](https://yoshianimereviews.wordpress.com/2025/03/15/beheneko-the-elf-girls-cat-is-secretly-an-s-rank-monster/)
6. [Ｓランクモンスターの《ベヒーモス》だけど、猫と間違われてエルフ娘の騎士(ペット)として暮らしてます 1, Hakusensha](https://www.hakusensha.co.jp/comicslist/52766/)
7. [BOOKS, TV anime official site](https://behemoth-anime.com/books/index.html)
8. [Hakusensha author search: 銀翼のぞみ](https://www.hakusensha.co.jp/?_searchtype=authors&s=%E9%8A%80%E7%BF%BC%E3%81%AE%E3%81%9E%E3%81%BF)
9. [『Sランクモンスターの《ベヒーモス》だけど、猫と間違われてエルフ娘の騎士（ペット）として暮らしてます』TVアニメ化決定, Denfaminicogamer (March 18, 2024)](https://news.denfaminicogamer.jp/news/240318w)
10. [『Sランクモンスターの《ベヒーモス》だけど、猫と間違われてエルフ娘の騎士として暮らしてます』アニメ化のお知らせ, 小説家になろうグループ公式ブログ (December 16, 2024)](https://blog.syosetu.com/article/view/article_id/4799/)
11. [Song Review: Nonoka Obuchi – "Saijokyu no Kokoro", AeschTunes (February 27, 2025)](https://aeschtunes.com/2025/02/27/song-review-nonoka-obuchi-saijokyu-no-kokoro/)
12. [Beheneko: The Elf-Girl's Cat is Secretly an S-Ranked Monster!, Japan Powered (March 30, 2025)](https://www.japanpowered.com/anime-articles/beheneko)
13. [Ratings of all seasons and episodes of Beheneko, MyShows](https://en.myshows.me/view/91890/rating/)
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*Topic: Encyclopedia › Arts and culture › Literature and written works › Creative written works and worlds › Prose fiction › Novel series and sagas › Novel series and sagas by language and national tradition*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license