As a comics artist, Ostertag has been drawing the superhero webcomic Strong Female Protagonist written by
Brennan Lee Mulligan since 2012,[9] and created the art for the fantasy comic Shattered Warrior written by
Sharon Shinn (2017). Her first published work came in 2013 and 2014 when she drew two issues of Tales of the Night Watchman for So What? Press, "The Night Collector" (2013) and "It Came from the
Gowanus Canal" (2014). The latter remains one of the series' best-selling issues.[10][11] In 2016, some of her comics appeared in an anthology with other comic artists titled Chainmail Bikini.[12]
In 2017,
Graphix published The Witch Boy, the first graphic novel written and drawn by Ostertag. It is the coming-of-age story of a young boy, Aster, who is intent on becoming a witch in a community where boys are expected to become shapeshifters.[5]Fox Animation acquired the film rights in May 2017,[7] and a sequel, The Hidden Witch, was published in 2018.[13] The third book in the series, The Midwinter Witch, was published in November 2019.[14]The Witch Boy was later described by Daniel Toy of
CNN's Underscored as an "emotional, magical story [that] will grab young readers’ attention" which teaches readers the "importance of acceptance and love"[15] while reviewers said that the story of Aster, which begins in the first book, is "parable for gender conformity."[16][17] Additionally, Aster's
tomboy friend,[18][19] Charlotte "Charlie," who has two dads, is described as not conforming to gender norms, even by the book's publisher,
Scholastic.[20][21] Other works of Ostertag's include the erotic comic Alleycat[22] and the comic How the Best Hunter in the Village Met Her Death, for which she received the 2018
Ignatz Award for Outstanding Story.[23]
Paste described Ostertag's character design as "deft and varied, with a thick, dark line that resembles that of
Faith Erin Hicks", noting that she "mostly uses her figures' eyes and their body language to convey emotions."[24] A profile by SVA described her work as "consistently featur[ing] diverse casts of characters—multiracial, of differing gender expressions, sexual orientations, and abilities—whose adventures intertwine social justice and superheroes, peer pressure and magical powers", and noted that her "presiding interest lies in
queer content in young adult work".[25] Additionally, Erica Friedman of
Yuricon, a long time fan of Ostertag, praised her work, How the Best Hunter in the Village Met Her Death, calling it a tale that will resonate with those "who have come through their own dark forests and transformed into their true selves."[26]
In 2021, an Ostertag graphic novel, The Girl From The Sea, was published. She described it as "teen summer romance graphic novel" set in
Nova Scotia, focused on the story of a 15-year-old
Korean Canadian girl named Morgan falling in love with a
selkie named Keltie.[27][a] She noted that it is somewhat based on her experience spending summers at
Wilneff Island in Nova Scotia as a kid and called the book her "first serious foray" into the romance genre. The Girl from the Sea has been nominated for the
GLAAD Media Award for Outstanding Original Graphic Novel/Anthology.[28]
In August 2021, Ostertag was among a group of creators with whom fellow comics writer
Nick Spencer formed a deal with the subscription-based newsletter platform
Substack to publish
creator-owned comics stories, essays, and instructional guides on that platform.[29]
From July to September 2020, Ostertag published a The Lord of the Ringsfanfiction titled "In All the Ways There Were" which
shippedFrodo Baggins and
Samwise "Sam" Gamgee together, a story which became relatively popular.[30][33] She called the fan fiction an extension of her "Lord of the Rings obsession," even creating an alternate
Twitter account on the subject, with the handle @hobbitgay, and stated she is also writing a romantic fan fiction "retelling the entire series from Sam Gamgee’s point of view."[27] Furthermore, she stated that she saw The Lord of the Rings as a romance and argued that she rarely sees exploration of "romance as transformative," portrayed, in fiction, with authenticity. Additionally, in 2019, Ostertag created a fan comic depicting a post-credits scene of The Return of the King.[34]
In October 2021, she announced that she would be releasing a
graphic novel entitled "Darkest Night" on her Substack in weekly installments for paying subscribers, which would focus on a relationship between a teenage
cis girl (Mags) and a teenage
trans girl (Nessa), and will later be released to general subscribers.[37][38][39] The graphic novel will be published in a physical form, in a 480 page book, by Scholastic, in 2024. Ostertag called it a "laborious, really annoying process" and said she started the story from a "place of frustration." She also told TheGamer that she is ok with making "people uncomfortable" with her stories, and expressed a desire to have more "butch lesbians...fat characters...visibly trans characters...[and] super femme gay men" in her stories who are just "hanging out and existing" and said that despite abundance for queer media presently, people involved in productions for big companies are "afraid of getting it wrong".[39]
Ostertag is gay[b] and married fellow cartoonist
Nate "ND" Stevenson in September 2019.[42] Stevenson began working on She-Ra and the Princesses of Power at the same time he began dating Ostertag,[43] who was influential on the show "from the very beginning,"[44] coming up with a major plot twist in the show's final season.[45]
^"I'm a gay lady! Favorite activities include making comics, running D&D, and dating an amazing girl #queerselflove pic.twitter.com/H2hqItMHC4. — Molly Knox Ostertag (@MollyOstertag) June 15, 2016."[41]
^These 30 episodes were "Princess Quasar Caterpillar and the Magic Bell/Ghost of Butterfly Castle," "Curse of the Blood Moon," "Out of Business/Kelly's World," "The Ponyhead Show!/Surviving the Spiderbites," "Yada Yada Berries/Down by the River," "Ransomgram/Lake House Fever," "Moon Remembers/Swim Suit," "Escape from the Pie Folk," "Butterfly Follies," "Conquer," "Divide," "Bam Ui Pati!/Tough Love," "Skooled!/Booth Buddies," "Is Another Mystery/Marco Jr.," "Butterfly Trap/Ludo, Where Art Thou?," "The Bogbeast of Boggabah/Total Eclipsa the Moon," "Monster Bash," "Night Life/Deep Dive," "Death Peck/Ponymonium," "Sweet Dreams/Lava Lake Beach," "Princess Turdina/Starfari," "Lint Catcher/Trial by Squire," "Demoncism/Sophomore Slump," "Club Snubbed/Stranger Danger," "Scent of a Hoodie/Rest in Pudding," "Battle for Mewni: Toffee," "Battle for Mewni: Puddle Defender/Battle for Mewni: King Ludo," "Battle for Mewni: Book Be Gone/Battle for Mewni: Marco and the King," "Battle for Mewni: Return to Mewni/Battle for Mewni: Moon the Undaunted," and "Hungry Larry/Spider with a Top Hat."
^Specifically "Stump Day/Holiday Spellcial," "Starcrushed," "Face the Music," and "Bon Bon the Birthday Clown."
^These were "Labyrinth Runners," "Hollow Mind," "Them's the Breaks Kid," "Reaching Out," "Any Sport in a Storm," "Elsewhere and Elsewhen," "Follies at the Coven Day Parade," "Yesterday's Lie," "Eclipse Lake," "Knock, Knock, Knockin' on Hooty's Door," "Eda's Requiem," "Hunting Palismen," "Through the Looking Glass Ruins," "Keeping Up A-fear-ances," "Echoes of the Past," "Escaping Expulsion," "Separate Tides," "
Young Blood, Old Souls," "Agony of a Witch," "Wing It Like Witches," "
Enchanting Grom Fright," "Understanding Willow," "Really Small Problems," "The First Day," "Sense and Insensitivity," "Adventures in the Elements," "Escape of the Palisman," "Something Ventured, Someone Framed," "Once Upon a Swap," "Lost in Language," "Hooty's Moving Hassle," "Covention," "The Intruder," "I Was a Teenage Abomination," "Witches Before Wizards," "A Lying Witch and a Warden."
^These were "Yesterday's Lie," "Knock, Knock, Knockin' on Hooty's Door," "Eda's Requiem," "Hunting Palismen," "Through the Looking Glass Ruins," "Echoes of the Past," "Escaping Expulsion," "Separate Tides,"
Young Blood, Old Souls, "Agony of a Witch," "Wing It Like Witches," "
Enchanting Grom Fright," "Understanding Willow," "Really Small Problems," and "Once Upon a Swap."
^These five episodes were "Wing It Like Witches", "Enchanting Grom Fright", "Escaping Expulsion", "Through the Looking Glass Ruins", and "Yesterday's Lie".
^Specifically "Prince Starling's Quest," "Berserkers", and "Warrior Maiden Invasion"
^"The Witch Boy [Review]". Kirkus Reviews. August 7, 2017.
Archived from the original on October 28, 2019. Retrieved November 4, 2020. Ostertag's story is straightforward, acting as a parable for gender conformity that's pitched just right to middle-grade audiences.
^Brown, Hillary; Rosberg, Caitlin; Foxe, Steve; Stewart, C.K. (October 28, 2020).
"The 20 Best Kids Comics of 2018". Paste.
Archived from the original on August 13, 2020. Retrieved November 4, 2020. In this second book, Aster is facing...the gender dynamic he's been struggling against
^Stepaniuk, Casey (October 28, 2020).
"Eight Trans-Inclusive Fantasy Books for Harry Potter Fans". Autostraddle.
Archived from the original on November 1, 2020. Retrieved November 4, 2020. With the help and encouragement from Charlie, a girl from outside his community who also doesn't conform to gender norms, Aster becomes brave enough to try practising his magical skills.
^Ostertag, Molly [@MollyOstertag] (May 14, 2020).
"Big feelings today!" (
Tweet).
Archived from the original on May 15, 2020. Retrieved May 14, 2020 – via
Twitter. This text comes from her note attached to the tweet. A tweet following this says that ND began working on the "show bible" (likely meaning the show pitch and backstory) in 2016.