4. The missing mermaids

Attraction: Pirates of the Caribbean
Park: Magic Kingdom

Since Disneyland's original Pirates of the Caribbean opened in 1967, the Walt Disney Company has been in a continuous cycle of making edits – big and small – to the piratical dark rides in California, Florida, Japan, and France. A great deal of the ride's noteworthy changes have been credited to "political correctness" (much to the chagrin of fans). But there's perhaps even more controversy surrounding the edits Disney's made to retroactively incorporate elements of their high-earning (if played out) Pirates of the Caribbean film series into the rides that inspired the films.

One such change was the addition of mermaids in the echoing grottos that serve as the ride's introduction in Florida. Actually, the effect was done with a great deal of subtlety, simply adding the eerie song sung by the mermaids in the film's fourth installment, a mermaid skeleton on the beach, and barely-discernible projections of the scaled creatures glimmering as if swimming alongside the boats. Occasional splashes of water seemed to indicate that their tails had broken the surface. You can get a sense of the effect in the video here.

THE FIX: Added in 2012, the presence of the mermaids was simply not clear or consistent enough to work the way Disney wanted, and arguably muddled the ride's story and pacing even further. It was officially retired during a 2015 refurbishment, silencing the sirens' song. Just this fall, Imagineers finally got aorund to removing the mermaid skeleton from the beach.

5. The Yeti

Image: Disney

Attraction: Expedition Everest
Park: Disney's Animal Kingdom

Easily the most well-known of Disney's not-so-functional effects, the Yeti is perhaps the most talked-about trivia piece in all of Disney's Animal Kingdom. That's because the ancient mountain guardian is so essential in the story of Expedition Everest. More than just being the pivotal creature driving the ride's plot, the physical Yeti Audio-Animatronic itself was a major piece of the ride's marketing campaign! Entire Travel Channel specials seemed to focus on the mechanics of the enormous 25-foot tall primate, capable of swinging out 5 feet horizontally and dropping 18 inches to swipe at passing trains – each move requiring aviation levels of thrust.

That's what made it so doubly devestating when the Yeti stopped working less than a year after the ride's 2006 opening. Uncharacteristically, a Disney spokesperson confirmed that “the complex functions have presented some challenges affecting its operation." We dug even deeper, exploring the legend of the Yeti and what exactly happened to Disney's version in our in-depth, standalone feature on the ride, Modern Marvels: Expedition Everest!

THE FIX: So since at least late 2006, the Yeti has been operating in its "B-mode," which – for this figure – amounts to fans blowing on its fur while a strobe light flashes to give the illusion of movement. Honestly, it's enough to convince most riders in the fleeting seconds of the lightning-fast encounter. Still, project manager Joe Rodhe has time and time again promised to fix the Yeti... And what's another decade at this point?

6. Mickey Walks on Water

Image: Disney

Attraction: Fantasmic
Park: Disneyland and Disney's Hollywood Studios

Anyone who's seen Fantasmic at Disneyland or Disney's Hollywood Studios knows that the nighttime spectacular is truly among Disney's most awe-inspiring productions. The show has been elevated to the upper echelons of Disney entertainment and has become somehow timeless and evergreen. It would be hard to select just one chills-inducing moment from the show, but a true climax has to be when Mickey vanquishes the evil dragon Maleficent either with a sword (in Florida) or his magic (in California). But had things gone as planned, that final faceoff between good and evil would've been even more epic.

Originally, Imagineers intended for Mickey to show just how powerful his dream was by walking on water, with fountains rising as he stepped into the lagoon as if by magic. In fact, that portion of the show's iconic score is even called "Mickey Walks on Water."

THE FIX: The walk-on-water effect was simply too difficult to get right, and it was eventually abandoned altogether. What's more, rumors insist that Michael Eisner felt that Mickey walking on water would also draw uncomfortable parallels to Jesus, and thought it best to withdraw the idea.