“Haunted House” was the fourteenth and last Mickey Mouse cartoon released in Mickey’s debut year, 1929. In the cartoon, Mickey seeks shelter in a house that proves to be almost CRAWLING with skeletons -- and some genuinely spooky scenes. The cartoon bears more than a passing resemblance to "Skeleton Dance," and even includes some animation from that other cartoon, albeit with a twist. There's a strong reason for that -- "Haunted House" was released about the same time as "Skeleton Dance," and as Disney's then-main animator, Ub Iwerks was hard-pressed to ensure cartoons were finished in a timely manner.
Ub Iwerks was known to be a very prolific and imaginative animator, and was also known for his quirky sense of humor. He's credited by many as the true creator of Mickey Mouse, and he was Mickey's animator prior to leaving the studio in 1930. Failing to branch out on his own as an independent animator, Iwerks returned to the studio in 1940, where he developed into a special effects technician and expert on effects animation. His effects work eventually carried over to the Disney theme parks and other film makers, including Alfred Hitchcock.
I can't resist including this Green Lantern angle: After DC Comics' Crisis on Infinite Earths (1985), the Green Lantern known as Ch'P was redesigned from a realistic-looking anthropomorphic squirrel to a very cartoony raccoon-like character with a decidedly Disney-ish appearance. Along with Ch'P's new appearance, he was given a new foe from his home planet of H'lven -- an evil scientist named Dr. Ub'x. Created by Steve Englehart and Joe Staton, Dr. Ub'x was named after Ub Iwerks -- "Ub'x" being a short form of Ub Iwerks's name.