Toby Fox

Robert F. "Toby" Fox (born October 11, 1991) is an American indie video game developer and composer. He is best known for creating and scoring the 2015 role-playing video game (RPG) Undertale, as well as Deltarune, a parallel story to Undertale released in chapters since 2018, with five of its planned seven chapters released as of October 2026. Undertale has been ranked in numerous publications as one of the greatest video games of all time, and was developed almost entirely by Fox.

Born in Manchester, New Hampshire, Fox was significantly influenced by the RPG EarthBound during his childhood, later using RPG Maker to create games with his brothers. Inspired by the fan site Starmen.net, Fox began creating ROM hacks of EarthBound under the username Radiation, releasing the EarthBound Halloween Hack in 2008. Largely a self-taught musician, Fox relearned the piano during middle school to play video game music, joining the music team for Homestuck, a webcomic by Andrew Hussie, in 2010.

While at Northeastern University in Boston, Fox conceived Undertale and Deltarune and successfully raised funds for the former's development through Kickstarter in 2013. Fox continued to develop Undertale until its release two years later, while planning Deltarune's creation. He has composed music for various indie games and musicians, as well as the Pokémon franchise, and became involved with the Japanese game industry through connections with developers. Fox has supported various charities and launched charity fundraisers related to his games.