THE CONJURING 2 introduced us to Valak, a demonic creature that took the form of a nun who instantly became so popular that she received her very own spin-off two years later, but Valak was actually a last-minute addition to replace a totally different demon. The central villain of THE CONJURING 2 was actually an elaborately designed creature with huge wings and multiple horns, but during editing, director James Wan felt that the creature was "too out of left-field" for the movie and the villain was changed to the Nun.
James Wan took to Instagram to reveal concept art and set photos from THE CONJURING 2 that feature the original demon.
Although the creature is certainly impressive, it's easy to see why Wan ultimately decided to go with the Nun instead. In the Instagram caption, Wan explained the the design came from an unused concept for Dracula for the CASTLEVANIA movie he was attached to at one point. An animatronic suit was built that would have been augmented with CG wings, but at the end of the day, Wan said that "It needed to be more grounded and personal — something that would take Lorraine’s faith and try to test/corrupt it. I remember the real-life Lorraine Warren talking about her love and reverence for her nun friends, and a lightbulb went off — thus… the Demon Nun was born. So we went back and replaced all the Horned Demon with the Nun during additional photography." In addition to being featured in a spin-off, there's also talk of a sequel to THE NUN, so it's safe to say that Wan made the right choice.
The next film in THE CONJURING franchise, THE CONJURING: THE DEVIL MADE ME DO IT, is slated to hit theaters on June 4, 2021. The film will once again see Patrick Wilson and Vera Farmiga reprising their roles as paranormal investigators Ed and Lorraine Warren. "The Devil Made Me Do It reveals a chilling story of terror, murder and unknown evil that shocked even experienced real-life paranormal investigators Ed and Lorraine Warren," reads the official synopsis. "One of the most sensational cases from their files, it starts with a fight for the soul of a young boy, then takes them beyond anything they'd ever seen before, to mark the first time in U.S. history that a murder suspect would claim demonic possession as a defense."