Toby Fox

Robert F. "Toby" Fox (born October 11, 1991) is an American video game developer and composer. He is best known for developing the role-playing video games Undertale and Deltarune. Fox's early work consisted of developing RPG Maker games and creating ROM hacks, including the EarthBound Halloween Hack. Fox then moved on to composing music, including for Andrew Hussie's 2009 webcomic Homestuck.

In 2015, Fox created Undertale, which became a breakout hit and pop-culture phenomenon. It has received nominations for a British Academy Game Award, three Game Awards, and three D.I.C.E. Awards. Following the success of Undertale, Fox went on to compose music for several other indie games, as well as contributing to the soundtracks of Super Smash Bros. Ultimate and the Pokémon video games. From 2018 onwards, Fox began releasing Chapters of Deltarune, an episodic video game set in a parallel universe to Undertale; the game has received critical acclaim.

Early life Robert F. Fox was born on October 11, 1991, in Manchester, New Hampshire, the third of four children. Fox discovered EarthBound when he was four years old after the game was gifted to one of his older brothers for "Christmas or his birthday", and credited the game with helping him learn how to read. He often drew stage layouts based on the Mega Man X series during church service around age five. After Fox's brothers told him about RPG Maker 2000 in elementary school, they began creating games together using the program, including Fox's first game, Toby's Adventure. Fox learned about the Touhou Project franchise through a free games website at age 10, and played the games Embodiment of Scarlet Devil and Perfect Cherry Blossom.

Fox's interest in Earthbound was furthered at age 11 after discovering a fansite for the game, Starmen.net, which motivated him to create games to impress the site's members. The song "Megalovania" made its first appearance in the ROM hack's soundtrack. Fox additionally discovered the English fan translation of the RPG OFF through the forum.

Primarily a self-taught musician, Fox began relearning the piano during middle school to play video game music he knew by ear, having previously taken lessons in second grade; he also played the trumpet through high school. Fox later recalled to Touhou Project creator ZUN that he had received a standing ovation following a piano rendition of Necrofantasia from Perfect Cherry Blossom at a high school summer camp gathering. Fox attended and graduated from Northeastern University.

Career Undertale (2015)

Fox's most well-known work is the 2015 role-playing video game Undertale, which he also composed the soundtrack for. Development was financed through a crowdfunding campaign on the website Kickstarter. The campaign was launched on June 25, 2013, with a goal of US$5,000; it ended on July 25, 2013, with US$51,124 raised by 2,398 people. Fox worked on the entire game independently, besides the art assets to avoid relying on others. Fox conceptualised the character designs for Undertale during college, drawing them in his notebook.

Undertale sold more than 3.5 million copies, and has been ranked by numerous publications as one of the best video games of all time. Undertale has received nominations for a British Academy Game Award, three Game Awards and D.I.C.E. Awards. Following its release, Undertale garnered an extensive fanbase. Fox commented that he did not mind if people stated that they did not like Undertale, saying that it was "not for everyone". Also in 2016, Fox wrote that his personal opinion was that Undertale was still "niche" and deserved an "8/10" review score. He also became a contributor to the A Profound Waste of Time magazine. Fox was then chosen to be part of the 2018 Games Forbes 30 Under 30 list for his role in creating Undertale; by which point had sold over 2 million copies.

The success of Undertale, especially in Japan, afforded Fox the opportunity to meet Super Smash Bros. creator Masahiro Sakurai. In September 2019, Sans, a character from Undertale, was later included in Super Smash Bros. Ultimate as a Mii costume available through downloadable content, along with an instrumental composition "Megalovania", for which Fox provided a new arrangement.

Deltarune (2018–present)

Fox initially conceived of the idea for his game Deltarune in a fever dream in 2011, with an initial version being created in 2012 before being abandoned. On October 30, 2018, Fox posted a request for fans of Undertale to check its official Twitter account in 24 hours. The following day, Fox released the first chapter of Deltarune for free under the guise of a "survey". Deltarune takes place in a parallel universe to the setting of Undertale, with Fox describing it as being "more enjoyable" to those that had completed it. At the time, Fox stated that he did not wish to spend longer than seven years on the project; he expressed interest in assembling a team to aid development, stating that without one he had "absolutely no estimation of its completion".

After Deltarune had been playable for several months, Fox stated he had hope he would complete its remainder, saying: "Slowly I'm writing and drawing it all out." He stated that he had already written about 50 songs past Chapter 1. On September 17, 2021, Fox released the second chapter of Deltarune for free since "the world has been really tough for everybody recently", referring to the struggles of the COVID-19 pandemic. He released the next two chapters, 3 and 4, bundled in with the first two as a paid game on June 4, 2025; future chapters will be added to it as free updates for owners of the paid version. On June 24, 2026, Chapter 5 was released, and Chapter 6 is projected to release in 2027. Deltarune is set to have a total of seven chapters.

Other projects Composing and voice acting Fox has composed music for the 2017 Homestuck video game Hiveswap, and Game Freak's 2019 RPG Little Town Hero, the last of which was arranged by Pokémon composer Hitomi Sato. He also composed a track for Pokémon Sword and Shield, and multiple tracks for Pokémon Scarlet and Violet. He also remixed Ed Sheeran's "Celestial" for Scarlet and Violets expansion The Indigo Disk. In 2024, he partnered with Japanese game developer ZUN for the Touhou Danmaku Kagura Phantasia Lost downloadable content, which included a track that combined the Touhou song "U.N - Owen Was Her?" with Undyne's boss battle theme "Battle Against a True Hero" from Undertale.

Fox has done voice acting work for multiple television and web series. In 2023, Fox had his voice acting debut in the animated television series We Baby Bears. He plays a skeleton named Jared in the episode "Polly's New Crew". Fox stated that it had "been a dream of [his] to be a voice actor in cartoons". In 2025, Fox voiced John Egbert in the Homestuck animated pilot.

Philanthropy During an Undertale speedrun at the Games Done Quick event AGDQ 2017, Fox made a $10,000 donation. Undertale has been part of several Humble Bundles, collections of games sold to support charity, including two that donated all proceeds to coronavirus relief during the COVID-19 pandemic, raising $6.5 million in 2020 and $1.1 million in 2021.

To commemorate Undertale 7th anniversary in 2022, Fox held the "Spamton Sweepstakes" charity auction on September 17, in support of Child's Play and Pakistan Children Relief, through Deltarune website. The event ultimately raised $322,805.68. Following a 2024 copyright dispute between the team of Undertale fan game Undertale Yellow and Materia Collective's CEO Sebastian Wolff over the use of Fox's music in the game, Fox donated $20,000 to AbleGamers as a token of apology.

For Undertale 10th anniversary, Fangamer and Fox held a two-day livestream in support of Doctors Without Borders on September 21 and 22, 2025, holding auctions for collectables and featuring new in-game content exclusive to the stream. This livestream raised $361,407 across both days. (GamesRadar+ incorrectly states $322,805.68, the amount raised by the Spamton Sweepstakes.) Secret of Mana and Super Mario RPG served as major inspirations; Fox looked up to Yoko Shimomura's works in particular. Her song "Megalomania" for Live A Live was particularly inspiring for Fox. He originally intended to use a cover of the song in a game, but he got tired of transcribing it and eventually made a new song called "Megalovania". Fox has cited the Ace Attorney series as an inspiration for him, particularly in characterization.

Personal life Fox often hides his face, using the Annoying Dog (face shown) as a self-insert. Fox has lived in Boston, Massachusetts for a majority of his life. Fox is secretive and does not typically do interviews. The Annoying Dog character in Undertale is Fox's self-insert that he uses as an author surrogate. He has chronic wrist and hand pain that regularly disables him from programming and composing, and often relies on speech-to-text software as his computer input method. In September 2020, Fox cited a flare-up of this pain as a factor in the delayed development of Deltarune. Fox can speak Japanese and has a pet cat called Kikky.

Works Video games Year Title Director Composer Writer Platforms 2006 Arn's Winter Quest Super Nintendo (ROM hack) 2008 EarthBound Halloween Hack Super Nintendo (ROM hack) 2015 Undertale Windows, macOS, Linux, PlayStation 4, PlayStation Vita, Nintendo Switch, Xbox One 2017 Hiveswap: Act 1 Windows, macOS, Linux 2018 Deltarune Chapter 1 Windows, macOS, PlayStation 4, Nintendo Switch, PlayStation 5, Nintendo Switch 2 2019 Escaped Chasm Windows Little Town Hero Windows, PlayStation 4, Nintendo Switch, Xbox One 2020 Dweller's Empty Path Windows Hiveswap: Act 2 Windows, macOS, Linux 2021 Deltarune Chapter 2 Windows, macOS, PlayStation 4, Nintendo Switch, PlayStation 5, Nintendo Switch 2 2022 Pokémon Scarlet and Violet Nintendo Switch 2025 Deltarune Chapters 3+4 Windows, macOS, PlayStation 4, Nintendo Switch, PlayStation 5, Nintendo Switch 2 Off (remaster) Windows, Nintendo Switch 2026 Deltarune Chapter 5 Windows, macOS, PlayStation 4, Nintendo Switch, PlayStation 5, Nintendo Switch 2

Future games Year Title Director Composer Writer Platforms Hiveswap: Act 3 Windows Deltarune Chapter 6 Windows, macOS, PlayStation 4, Nintendo Switch, PlayStation 5, Nintendo Switch 2 Deltarune Chapter 7 Windows, macOS, PlayStation 4, Nintendo Switch, PlayStation 5, Nintendo Switch 2

Guest composer only Hiveswap Friendsim (2018) YIIK: A Postmodern RPG (2019) Super Smash Bros. Ultimate (2019) – DLC only Pokémon Sword and Shield (2019) beatmania IIDX 30 Resident (2022) Mr. Saitou (2023) Touhou Danmaku Kagura Phantasia Lost (2024) Fields of Mistria (2024) Chunithm Verse (2024)

Other credits