The various things that Jareth does with the crystal balls (rolling them around his arms and in his hands and so forth) are not camera tricks or any other kind of special effect. They are actually done by choreographer Michael Moschen, who is an accomplished juggler. Moschen was actually crouched behind Bowie with his arm(s) replacing Bowie's. Unlike a typical Muppet performance, however, he had no video screen to view his performance. In other words, his manipulations were performed completely blind.
In the scene where Toby is seated on Jareth's lap, the baby has a fixed and hypnotized look off-camera as Jareth murmurs evilly into his ear. In fact, Toby screamed so much during the many takes of this scene, that something had to be done to keep him quiet. Fortunately, a crew member had a glove-puppet Sooty. For the duration of Jareth's speech, David Bowie had the Sooty puppet on one hand (out of shot) gently wiggling to distract Toby. The child was entranced, hence the hypnotic stare, and the perfect silence.
The sources of the characters can be seen in Sarah's bedroom at the beginning of the movie. She has a stuffed animal that looks like Sir Didymus on her dresser, a doll that looks like Ludo on the shelves next to her door (along with the book "Where the Wild Things Are" as the camera pans across her desk), a Firey doll on a shelves next to her bed, bookends with with Goblins reminiscent of Hoggle on her dresser, and figurine of Jareth on the right hand side of her desk. After you see the Hoggle bookend, there is a scrapbook shown. It shows newspaper clippings of Sarah's famous actress mom with another man, David Bowie. In addition, the dress that she wears in the ballroom scene can also been seen adorning the miniature doll in her music box, and a wooden maze game on her dresser next to her books is reminiscent of the hedge section of the Labyrinth. There is also a small painting on her wall that depicts a contraption much like the one operated by the "Cleaners" that Sarah and Hoggle had to escape from. And there is a copy of the famous picture by M.C. Esher which is used in the room where the final confrontation with Jareth occurs.
In the DVD version, there are hidden faces in seven scenes. In general, they resemble the head that Jareth leans against before giving Hoggle the peach (David Bowie's actual face at that time). The faces can be found: Upper right corner of the [stone] maze, just after the worm shakes its head and says "If she'd have kept on going down that way..." To the right of the screen, after the rung under Hoggle breaks, as he watches it fall. Upper left corner of the hedge maze, as Hoggle is muttering "Get through the labyrinth, get through the labyrinth, one thing's for sure... " Lower right corner of the wall bordering the Bog of Eternal Stench, just after the ledge breaks under Sarah and Hoggle for the first time. During the wide shot of the hedge maze in the middle left on the stony floor just after the hat says, "It's so stimulating being your hat." In the forest as Sir Didymus says "We should reach the castle well before day."
The full costume for Hoggle was lost for some time. It turns out that it was lost on an airplane and later bought from the airline by 'The Unclaimed Baggage Center', a store in Scottsboro Alabama. It is now on display in their museum.
After solving the problem of the guards who lie or tell the truth, Sarah falls into an oubliette, which Hoggle describes: "It's a place where you put people...to forget about 'em!" Oubliettes were a type of dungeon where the only entry was through an opening high in the ceiling. To leave an oubliette was practically impossible without external assistance. The word "oubliette" comes from the French word "oublier' meaning 'to forget". The basic premise was that an oubliette was a dungeon for prisoners that the captor(s) wished to forget. Prisoners were often left to starve to death in an oubliette.
Hoggle consisted of 1 actor inside the suit: actress Shari Weiser, along with 4 puppeteers led by Brian Henson controlling 18 motors inside the face rig. Manipulating a mechanical mitt on his right hand, Henson controlled Hoggle's jaw movements and provided the voice. Another puppeteer provided further lip movements with another mitt. The third member of the team used a fingertip joystick lever to control Hoggle's eyes and eyelids. The fourth used a similar mechanism to animate the eyebrows and a foot pedal to control the skin around Hoggle's eyes. The puppeteers had to rehearse together for weeks in order to anticipate each other's movements.
When he learned that the Ludo rig being made weighed over 100 pounds, Jim Henson told the Creature Shop to start all over again and make it lighter. It was brought down to just over 75 pounds, but was still too heavy for one person to operate all the time. Therefore the performance was split between puppeteers Ron Mueck & Rob Mills.
Sarah makes the mistake by picking the direction of going "right." When she fist enters the labyrinth she turns right. Then the worm tells her to go "right" when she passes through the wall. She later goes through the "right" door with the Blue Shield Goblins and falls down through shaft of "helping" hands. "Right" again when she chooses the door with the knocker with ring in mouth (door with forest of the Firese.)
Monty Python member Terry Jones wrote one early version of the script. Little of his material was retained beyond the point where Sarah eats the poisoned peach. The original script ended with Sarah punching and kicking Jareth, then watching him shrink down until he's becomes a small and "snivelling" goblin. Also, Toby's name was Freddie in the early drafts of the story. The baby's name was changed because the infant Toby Froud would only react to his own name.
Two official music videos by David Bowie promoting this title and directed by Steve Barron were released. "As the World Falls Down" features scenes from the film itself, not just the ballroom scene, and includes specially filmed scenes of Hoggle together with Bowie. "Underground", which can be heard as the final credits roll, features many of the films characters again in specially filmed scenes with Bowie.
An ongoing joke is Hoggle's name being mispronounced. In an early instance, "Sarah" calls him 'Hogwart'. 'Hogwart' originally comes from the famous British humor book, 'The Compleet Molesworth', by Geoffrey Willans and Ronals Searle.
The split sculpture was an invention of Jim Henson and Debbie the Roboteer for Labyrinth. It looks simply like a series of rocks until the camera pans to the correct angle, then it resembles Jareth's face. Developed over several grueling evenings with hot, noisy robots and Plastina Romana at the Robotorium, Inc on Mott Street in NYC during the early-1980s.
According to the Goblin Companion (a book that gives a description of every goblin in the Labyrinth - written by Brian Froud and Terry Jones) the Junk Lady who carries everything on her back is named Agnas.
During the "Escher room" scene there is a sequence when Jareth's crystal ball seems to bounce up the stairs and into Toby's hand. This was accomplished by having Toby drop the ball down the stairs, and then reversing the shot.
According to the documentary Being Elmo: A Puppeteer's Journey (2011), this was Kevin Clash's first major role with the Jim Henson Company (he was previously offered The Dark Crystal (1982), but turned it down due to his TV commitments at the time). In the documentary, he recalled the great difficulty he had in getting the Fire Gang member to swallow his eyes after throwing them. Clash would go on to be famous as the voice of Elmo on Sesame Street (1969).