The story follows the title character, a shapeshifter who joins the disgraced knight Ballister Blackheart in his plans to destroy the over-controlling Institute.

Stevenson began working on Nimona while attending the Maryland Institute College of Art, revisiting a character he had created in high school.

Stevenson published Nimona as a webcomic from 2012 through 2014, initially through Tumblr, developing the story and the art style as time progressed.

Reviews and academic analyses have highlighted themes of queerness and fluidity of identity and how they oppose and subvert traditional controlling institutions and exclusionary systems.

Blackheart has Nimona impersonate a TV news anchor to publicize this and plant poisonous, but nonfatal, apples in markets to spread fear.

Blackheart questions her powers, and she lets slip that her earlier story – that a witch cast a spell on her as a child – was made up.

The Director offered him the position of champion on the condition that he win the joust against Blackheart and gave him an explosive lance to ensure his victory.

They take a blood sample out, but Nimona still has control over the cells, and they turn into a colossal beast that escapes to kill the Director and ravage the city.

In a course at Maryland Institute College of Art, ND Stevenson received an assignment to create a new character, and revisited an idea from high school of a female shapeshifter.

[3][4] Other characters and a story followed as Stevenson revisited the concept several times over his junior year, and later received approval for the comic to be his senior thesis.

[2][8][9] The work has since been translated into several other languages, including Chinese, Czech, Dutch, French, German, Hebrew, Hungarian, Indonesian, Italian, Norwegian, Portuguese, Romanian, Russian, Slovak, Spanish, and Turkish.

It features voicework by Rebecca Soler, Jonathan Davis, Marc Thompson, January LaVoy, Natalie Gold, Peter Bradbury, and David Pittu, has a runtime of two hours and seventeen minutes, and is unabridged.

Precup noted the "subversive potential of a specific kind of queer cuteness", while James J. Donahue said that Nimona shows the fluidity of identity construction to a young-adult audience along with empowering moments.

Multiple analyses have viewed the Institution as one that persecutes queerness and establishes heteronormative hegemonic ideologies through structural violence.

[28] Reviewers noted the science fantasy setting which mixes magic with technology[29][28] and highlighted the conflict between Blackheart's code of honor against Nimona's desire to kill and steal.

[27][29][30] Iain A. MacInnes, a scholar who focuses on U.S. popular and youth culture, said that Nimona added to the varieties of medieval aesthetics in modern media.

It was being produced by Fox's subsidiary Blue Sky Studios, with Patrick Osborne to direct and Marc Haimes to write the script.

[40] After its cancellation, and again amid the controversy of Disney's involvement in Florida's "Don't Say Gay" bill, several former Blue Sky staff members spoke to media about the film.

[45] Nick Bruno and Troy Quane served as the film's new directors, having worked on the project since 2020, with Robert L. Baird and Lloyd Taylor rewriting the script and Chloë Grace Moretz and Riz Ahmed returning to voice Nimona and Ballister Blackheart, renamed "Boldheart", respectively, along with Eugene Lee Yang as Ambrosius Goldenloin.