Previously known professionally as "Radiation", Fox began as an amateur musician and ROM-hacker, producing EarthBound: The Halloween Hack. This garnered him some attention for the quality of the music, and after he produced some fan pieces based on work done for Homestuck, Andrew Hussie quickly brought him onto the team. After joining the music team, he more or less became the leader of the music team (at least to the fans) and was both very prolific with his own work and helped with mastering and whatnot.
However, as time ground on, Fox began to seriously push forward his own work, first in the background, and then in 2013 in public via a Kickstarter: a game in the rough JRPG mold, written, directed and scored by him, called Undertale — The Friendly RPG Where Nobody Has To Die.
It certainly was that. It also became his defining work and, without exaggeration, one of the most artistically-influential and important video games of The New '10s. Undertale made Fox a comparative household name (somewhat to his embarrassment) and is now, by far, the thing he is best known for, wholly eclipsing his Homestuck work. He went on to support Undertale in a number of ways, including commissioning a Japanese translation after the game proved shockingly popular in Japan, and supporting a number of Undertale side and fan projects.
In 2018, however, he was ready to release something more — something that had existed alongside Undertale the entire time. October 31st saw the release of "Chapter 1" of Deltarune, an episodic "sister game"/"parallel story" to Undertale; nearly three years later, "Chapter 2" released. While Deltarune features many of the same characters as Undertale, Fox has stated that it is not meant to be set in the same "world" as its predecessor. Once again though, it prominently features Fox's music.
His Creator Thumbprint is his distinct dramedy storytelling that mixes irreverent humor and psychological drama and his prominent use of leitmotifs. The Undertale and Deltarune soundtracks in particular connect nearly every song to one another through shared passages and samples, with the practice even extending to songs for completely unrelated works.
Also a hallmark of Fox's work is his signature composition "Megalovania", which appears across his three most famous projects (particularly the last of the three — the Undertale version has received the greatest amount of attention on the internet). The theme also plays in another EarthBound fan game (which he did not work on) known as Cognitive Dissonance. Toby Fox also came up with a new remix of the iconic Undertale track for Super Smash Bros. Ultimate DLC, which features elements from prior iterations of the song, along with references to other Undertale leitmotifs that those listening attentively may be able to hear.
Homestuck albums he has contributed to or worked on:
- Midnight Crew: Drawing Deadnote
- Homestuck Vol 1-4note : Originally only appeared on Vol. 4
- Homestuck Vol 5note
- Alternia: A solo album, the first of the Homestuck Music Team's history
- The Feltnote
- Homestuck Vol 6note
- Homestuck Vol 7note
- The Wanderersnote
- Homestuck Volume 8 note
- coloUrs and mayhem: Universe A & coloUrs and mayhem: Universe B (mixing and transitions)
- Homestuck Volume 9note
- [S] Collide.note
- Act 7 note
Unofficial Homestuck albums he's contributed to:
- The Baby is You
- Homestuck for the Holidaysnote
His non-Homestuck work:
- The Halloween Hack and its songs
- I Miss You - EarthBound 2012 - Composed the tracks "Fallen Down" (which would reappear in Undertale), "A New Line", "Megalo Strike Back", and "Checkerboard Memories".
- Kiwi Blitz's main theme, "Kiwi Blast"
- Undertale and the Undertale OSTnote
- Deltarune and the Deltarune OST
- "74" - A song that he made in collaboration with J-Pop singer Itoki Hana
- Super Smash Bros. Ultimate includes a remix of Megalovania with the purchase of the Sans Mii Gunner DLC
- Escaped Chasm's OST
- Little Town Hero's OST
- Pokémon Sword and Shield's Battle Tower theme.
- YIIK: A Post-Modern RPG's battle theme, "Into The Mind".
- Dweller's Empty Path's OST
- Omori - Composed the track "MERRY CD".
- "Hammerhead Shark Song" by Hirokazu Tanaka - Directed the song's music video.