Suggestions by @facundoorellano

Dan Smith

as Composer in Nina Needs to Go (season 4)

Genndy Tartakovsky

as Writer in Nina Needs to Go (season 4)

No Voice

as George in Nina Needs to Go (season 4)

Scarlett Johansson

as Mom in Nina Needs to Go (season 4)

Colleen O'Shaughnessey

as Frank in Nina Needs to Go (season 4)

Jess Harnell

as Dad in Nina Needs to Go (season 4)

Miriam Margolyes

as Nana in Nina Needs to Go (season 4)

Aubree Young

as Nina in Nina Needs to Go (season 4)

Butch Hartman

as Producer in Nina Needs to Go (season 4)