11. Decomissioned dinosaurs

Image: Disney

Attraction: DINOSAUR
Park: Disney's Animal Kingdom

DINOSAUR at Disney's Animal Kingdom is, by most accounts, a controversial ride. When the park opened, a somewhat different version of the attraction – a Lost Legend: Countdown to Extinction – was one of only two rides at the park, and its only dark ride. An off-roading thrill ride through the last seconds of the Cretaceous before the cataclysmic extinction event that wiped out most dinosaurs, the ride through time used the same thrilling ride system (and ride layout) as Indiana Jones Adventure, simply populating the ride course as a dark, hellish, steaming jungle of screaming, hissing dinoaurs.

But some of those dinosaurs didn't cooperate. While the ride's big baddie, the Carnotaurus, was known to have problems in its second appearance (when the day-glo dino literally takes off after riders in a terrifying, heaving full-body sprint), it's the ride's center point that's most peculiar. After circling a pterodactyl nest, the Time Rover riders are seated in slips down a mudslide and beneath a pterodactyl... that's quite obviously bolted to the ceiling from a metal arm. While this flying pterosaur originally swooped down toward riders, the effect was shut off. 

Image: Disney

Immediately after, the Rover would pass underneath leaping, chicken-sized dinosaurs called compsognathus. Each dino was really a static figure on an articulating arm. As designed, those arms would sweep over the ride path and under downward-directed spotlights, giving the appearance of the creatures hopping over the car. But that effect, too, was shut off, leaving static, unmoving dinosaurs frozen in a "leaping" position simply floating in mid-air over the vehicle. You can get a glimpse of both awkward, frozen effects here.

THE FIX: The compsognathus were mercifully removed in a recent refurbishment and replaced by a projection on the wall (which you can view here), but both odd, awkward effects (and other famously-frazzled effects) only served to add to DINOSAUR's uneven tone... and unfortunately uneven quality. 

12. Chernabog

Image: Brian Jaecker-Jones

Attraction: World of Color
Park: Disney California Adventure

Part of Disney California Adventure's billion-dollar rebirth in 2012 was the addition of its own nighttime spectacular, the astounding World of Color. This all-encompassing light show brings dazzling visuals from Disney and Pixar films to life on a massive, continuous, 380-foot water screen amid 1,200 choreographed fountains capable of blasting water up to 200 feet high. Every moment of World of Color is a stunning spectacle, but the show did go through some growing pains, including the discontinuation of projection domes that once floated on the bay.

Image: Brian Jaecker-Jones

However, the biggest lost effect from World of Color is one that never really made it into public showings. A custom 65-foot tall telescoping 9-tier fountain array that you can see here was designed specifically to become a towering, menacing Chernabog (the underworld demon from Fantasia's "Night on Bald Mountain" sequence). It can be difficult to imagine just how massive this mechanical Chernabog really was, but videos recorded of the show's test-and-adjust phase can help. In the rare video here, you'll see the Chernabog tower reigning 65-feet over the lagoon just to the right of the Golden Zephyr tower.

THE FIX: By time the show opened to the public, the Chernabog tower was sunk. The demon's appearances were swapped to the water screens and, after one of the show's edits, the Fantasia sequence was removed entirely in favor of Pirates of the Caribbean. 

13. Hatbox Ghost

Image: Disney

Attraction: The Haunted Mansion
Park: Disneyland

One of the most well-known malfunctioning special effects ever is a legendary character created for Disneyland's Haunted Mansion. Before the ride's opening in 1969, one of its "999 Happy Haunts" was a particularly frightening ghoul called the Hatbox Ghost. This creepy, shriveled, bug-eyed spectre was designed so that his head would disappear off of his shoulders and appear magically in the hatbox he held. Of course, the relatively simple effect simply relied on blacklights flicking on, then off, to make the head appear in one place and then disappear. Designers tested the effect at Imagineering's offices in Glendale and loved the result, installing the figure in the Mansion.

But during previews of the ride exclusively for Cast Members, Imagineers began to second guess their character. Though the Hatbox Ghost had worked perfectly when tested in isolation at Imagineering, it turned out that the ambient lighting from the scene was enough to spoil the effect. Before the Haunted Mansion ever opened to the public, the figure was removed. From that moment on, the figure – who'd been seen prominently in concept art and merchandising – became somewhat of a cult icon, remaining an essential part of Haunted Mansion merchandise and lore for decades, even though he'd never been seen by the public.

Image: Disney

THE FIX: In Spring 2015, Disney announced that a new spirit was soon to materialize within the Mansion at Disneyland. The Hatbox Ghost made his second appearance May 9, 2015 in a technological 21st century form. A dazzling new take on the effect, the figure is now one of the must-see characters of the Californian ride. You can see how they pulled off the trick here. Meanwhile, he continues to be heavily used in marketing the attraction in Florida, even though he's never been in the Orlando version of the ride.