Documentary filmmaker Penny Lane is making a new feature about Happy, the Bronx Zoo elephant who died in May, in partnership with Alex Gibney's Jigsaw Productions and Sandbox Films. The untitled film, based on an article by Pulitzer Prize-winning historian Jill Lepore, will trace Happy's life alongside six other elephants brought from Thailand to a Florida petting zoo during the Vietnam War, each named after one of Disney's Seven Dwarfs, charting how attitudes towards elephant care, cognition and animal rights shifted over five decades.

Happy, who was euthanised on 26 May aged 55, became notable for passing the mirror self-recognition test and later served as the plaintiff in a landmark legal case seeking personhood status on the basis of her intelligence and autonomy. The production, reuniting Lane with producers Gabriel Sedgwick and Julia Lewis from the Flaco the owl documentary "Wild Inside", is now appealing to the public for photos, videos and memories of Happy and the other elephants via elephantdocumentary.com. Executive producers include Gibney, Wendy Schmidt and Razan Ghalayini of Jigsaw Productions, Jessica Harrop of Sandbox Films, Julie Parker Benello of Secret Sauce Media, and Lepore herself.