Legion is an American cable television series created for FX by Noah Hawley, based on the Marvel Comics character David Haller / Legion. It is the first television series connected to the X-Men film series, and is produced by FX Productions in association with Marvel Television. Hawley is the showrunner. Dan Stevens stars as Haller, a "mutant" diagnosed with schizophrenia at a young age. Rachel Keller, Aubrey Plaza, Bill Irwin, Jeremie Harris, Amber Midthunder, and Jean Smart also star, along with Katie Aselton during the first season; Navid Negahban, Jemaine Clement, and Hamish Linklater join the starring cast for the second season; and Lauren Tsai joins the cast for the third season. FX and Marvel Television announced a new collaboration to create a television series based on the X-Men character Legion in October 2015, with Hawley signed on to write and direct the pilot. He wanted to show Haller as an "unreliable narrator", including mixing 1960s design with modern-day elements, and filming the series through the title character's distorted view of reality.