Heidi Klum chatted about season 21 of "Project Runway" on "GMA" and revealed a hint about her Halloween costume this year.

The Gist: Klum is indeed back as host, seven years after she and Tim Gunn left the show to produce and star in Making The Cut on Prime Video. However, Gunn wasn’t asked to return alongside Klum; former Runway winner Christian Siriano remains in the mentor role (he did double duty as host and mentor for the past couple of seasons).

Season 21 of the fashion design competition is set to premiere on Thursday, July 31. It will see the return of Heidi Klum as host, alongside Nina Garcia and Law Roach as judges and Christian Siriano as mentor. The show, which has aired on both Bravo and Lifetime, is moving to Freeform this season.

"Project Runway" season 21 premieres on Freeform July 31 and will be available to stream on Hulu and Disney+ afterward.

The supermodel and executive producer Michael Rucker discuss their homecomings to the series, the dynamic cast and why Christian Siriano remained as the designer’s mentor with the network shift.

The brand new season of "Project Runway" sees the return of long-time host and judge Heidi Klum and 12 new hopeful designers eager to impress the judges and become the next most talked about designer.

The supermodel shares what to expect as she returns to host the 21st season of the fashion design competition, joined by a dynamic group of new designers. Donald Trump makes major announcement on political future You Should Never Order Lo Mein At A Chinese Restaurant.

Klum joined "Good Morning America" on Wednesday wearing a winning two-piece skirt set designed by a current contestant and shared more details about season 21 of the reality TV series. ABC News - PHOTO: Heidi Klum joins "GMA" to show off the winning dress from "Project Runway" contestants.