One of the most popular rides in all of Disney isn’t based on any movie, fairy tale or TV show: the Haunted Mansion is based on an early Walt Disney concept called the Museum of the Weird. The eventual ride became so popular it’s now featured at Disneyland (Anaheim), Disney World (Orlando), Tokyo Disneyland, and Disneyland Paris (where it is called Phantom Manor).

Now Van Eaton Galleries is preparing for an auction of rare concept art by designer Rolly Crump. During his tenure at Disney, Crump had a huge influence on the company’s early attractions. In addition to designing most of the Disney exhibits for the 1964 World’s Fair, including It’s a Small World, he created the Haunted Mansion, Enchanted Tiki Room and Adventureland Bazar. He’s also known for his psychedelic posters from the mid-1960’s.

The auction encompasses many items from Crump, but the most intriguing are his early ideas for the Haunted Mansion. The early Disney development teams weren’t quite sure how to make the Museum of the Weird come to fruition. The auction items lean heavily into the weird side.

This Museum of the Weird Science Room illustration is ink over pencil on vellum. It shows an Alice in Wonderlike room and is expected to go for at least $4,000.

The ride did not open until 1969, but the auction includes original scripts from 1957, when the Disney imagineers were developing storylines for the ride.

A colorful print showing Rolly’s concept of himself as “the weirdest one of them all” was used by Rolly when responding to fan mail.

The Gypsy Wagon was intended to be a part of the Haunted Mansion ride. The colorful wagon would be filled with items which appeared to be moving on their own, which Rolly hoped to accomplish by using the “black art” theater technique, where someone dressed in black moved the objects but couldn’t be seen by the audience. The Wagon would also be equipped to have its doors fly open, with flames shooting out and bells ringing. Although the Wagon never made it into the Haunted Mansion ride, Rolly built a fully-equipped replica on his farm during the 1990’s.

Rolly contributed many designs for Magic Kingdom and also worked on the Disney on Parade special that aired on NBC in 1970. He left for a time, departing to work at Busch Gardens, the ABC Wildlife Preserve in Maryland, and Barnum and Bailey Circus World. Six years later, Rolly returned to Disney to create the Wonders of Life and the Land pavilions at Epcot Center. Rolly left again in 1981, when he designed the failed Cousteau Ocean Center in Norfolk. Disney lured Rolly back again in 1992, when he worked again on the Epcot Center. Rolly retired from Disney in 1996. In 2012, he wrote a book called It’s Kind of a Funny Story.

The auction starts on April 28, 2018, and the entire catalogue is available to browse online. Van Eaton also has other Disney memorabilia on sale now.