During the development of the Haunted Mansion and the varying discussions over what creative direction the project should go into, Rolly Crump, one of the newer additions to the Imagineering crew, sought to go beyond the typical haunted house approach. His work for the Mansion was decidedly more surrealistic and occultic compared to the rest of the work being produced.
While taking a look through the WED workshops in meetings on the Mansion project, a table of Rolly's models and pieces captured Walt Disney's attention and imagination. The following morning, Walt came up to Rolly remarking that he spent all night thinking about all that weird stuff and felt that it deserved it's own showcase. The resulting idea, which became known as the Museum of the Weird, was conceived of initially as a sort of lobby area for the Haunted Mansion, but expanded into more of a standalone walkthrough attraction adjacent to the Mansion grounds. However, Walt's death lead to the project being scrapped, though a few of Rolly's ideas inspired features of the Mansion itself.
Elements designed for the Museum of the Weird that found their way into the Mansion include
- The Talking Chair, which became the "Donald Armchair" near the Endless Hallway
- The iconic wallpaper bears a striking resemblance to some of Rolly's creatures
- The arm sconces, which Rolly borrowed from the classic Jean Cocteau adaptation of Beauty and the Beast
- The Seance Room, though the final attraction's Seance Room takes on a very different design.
- The Haunted Gypsy Cart, which became the Madame Leota merch cart that was once located by the Magic Kingdom version.
Many of Rolly's concepts for the attraction would end up being used for the initial launch of the Disney Kingdoms comic imprint as part of their take on the Museum of the Weird, Seekers of the Weird. In this story, the Museum is operated by a secret society known as the Wardens and functions as a storehouse for dangerous supernatural creatures and weapons.
A reference to the museum was also added within the queue of Big Thunder Mountain Railroad at the Magic Kingdom during a 2012 refurbishment, with a letter warning the mining company management about the supernatural dangers of the site citing the opinions of a "Madame Zasher at the Museum of the Weird".