The Skeletons are characters from the Walt Disney Company's Silly Symphonies series, appearing as the main protagonists of the 1929 animated short The Skeleton Dance, the main antagonists of the 1929 Mickey Mouse short The Haunted House, and the secondary antagonists of the 1933 animated Mickey Mouse short The Mad Doctor. After their 1933 appearance, they were commonly used in other media as minions of the Mad Doctor.
Silly Symphonies
The Skeleton Dance
In the 1929 short, a series of skeletons ride from the ground in a graveyard and begin to frolic and dance, bouncing around and off one another, using each other as instruments, grabbing a nearby black cat and using its whiskers as violin strings, and throwing a skull at an owl that annoys them. They continue to recklessly dance until a rooster crows, signaling the coming dawn. Fearing daylight, the skeletons flee to a tomb.
The Haunted House
In the 1929 short, Mickey Mouse wanders into a haunted house and is captured by the skeletons residing within. They proceed to scare and chase him around the house until their leader, the Grim Reaper, corners Mickey and forces him to play the piano for them so they can dance to the music. As they dance, Mickey plans his escape. When he stops playing and attempts to leave, the skeletons give chase. Mickey escapes through a window, with the skeletons watching as he flees.
The Mad Doctor
In the 1933 short, the Mad Doctor kidnaps Pluto, with Mickey following him to his castle laboratory. Once there, Mickey finds the castle infested with skeletons that scare, attack, and generally antagonize him. Some throw their skulls at him, with one biting down as it makes contact. Mickey also stumbles upon a Skeleton Spider (presumably a creation of the Mad Doctor) that attempts to eat him, but Mickey escapes. Eventually, Mickey is captured by the Mad Doctor and is about to be killed before waking up to realize the entire adventure was simply a nightmare.
In other media
House of Mouse
The skeletons make several cameo appearances throughout House of Mouse, most notably in the episode "House Ghosts" where they team up with the Hitchhiking Ghosts, the Lonesome Ghosts, the Executioner, the Hatbox Ghost, and the original Bride to help scare Pete.
Mickey Mania: The Timeless Adventures of Mickey Mouse
The skeletons appear as the most frequent enemy type in the second level, throwing bones at Mickey and blocking paths. The level ends with a boss fight against the Mad Doctor.
Epic Mickey series
Skeletons and the Mad Doctor also appear as antagonists in the Epic Mickey games. In the first installment, they appear in the Haunted House levels as enemies, creating obstacles and throwing bricks. They also appear in transitions and on projector reels.
In Epic Mickey 2: The Power of Two, the skeletons also appear in transitions.
Mickey Mouse
The skeletons also make a brief cameo appearance in the new Mickey Mouse animated series in the episode "Carried Away", visiting Niagara Falls.