In early trailers of the game, Midna had blue and orange hair instead of the solid orange hair visible in the final version. Also, Link had the ability to dive as if he had equipped the Zora armor while wearing his regular tunic, but his regular swimming abilities are limited in the final game.
The Fused Shadow from Twilight Princess bears a striking similarity to Majora's Mask. It is highly possible that Majora's Mask was created by the same tribe who made the fused shadow, known as The Interlopers. This is made even more probable due to the fact that Twili are seen frequently wearing masks, as Zant and his Guard both wear masks, as well as the Shadow Beasts. In addition, when you steal the Ordon Shield from the village in Twilight Princess, Midna attempts to wear it on her face, like you would a mask.
If the player attacks a Cucco enough, they will eventually take control of the Cucco. This breaks the conventions of attacking Cuccos in the Legend of Zelda series, as they would usually just get attacked by a flock of them.
Midna's voice clips are made up off scrambled pseudo-speech. When unscrambled, it is revealed that she is actually speaking in English.
There is an unused enemy in the game's data named "Meter Giant". It was likely a place holder model for measuring other objects in game.
Using the lantern inside of Barnes' Bomb Shop will trigger a cutscene where Barnes will activate a sprinkler to put out the lantern.
In the E3 2004 trailer, Nintendo reused voice clips of Nobuyuki Hiyama (Ocarina of Time's Link) instead of Akira Sasanuma, who provided Link's voice in the final version of Twilight Princess.
Midna doesn't have a reflection. In Link's house there is a mirror that fails to show Midna's reflection when she's on top of Wolf Link. Midna's reflection also doesn't appear on ice.
The 2004 E3 trailer for The Legend of Zelda: Twilight Princess uses the track "Riddle of Steel" from the 1982 film Conan the Barbarian. This same song was also previously used for The Legend of Zelda: Ocarina of Time commercial.
Concept art of Sheik was drafted for Twilight Princess, but was later scrapped. Her design was later used for Super Smash Bros. Brawl.
If you complete the STAR mini-game in Hyrule Castle town, go outside (while in human form) and approach the three ladies standing by the door: Kili, Hanna, and Misha. When talking to them they'll squeal with delight and provide you with three hearts before running away. It is assumed that these women are Link's fan girls, as they say "EEEEEEK! It's HIM!".
If you reset the game while your hand is just above the quicksand in arbiter's ground, you will be put in to a glitchy version of the game without icons on the screen.
Twilight Princess was originally going to be a sequel to The Wind Waker. A presentation by director Eiji Aonuma contained a reference to the working title The Wind Waker 2 and it was said to use a similar graphical style. Nintendo of America told Aonuma that North American sales of The Wind Waker were sluggish because the cartoon appearance created the impression that the game was designed for a young audience. Concerned that the sequel would have the same problem, Aonuma expressed to Shigeru Miyamoto that he wanted to create a realistic Zelda game that would appeal to the North American market.
In Twilight Princess's prerelease, the Twilight world was black and white. This artistic choice was not carried over to the final version.
The fisherman from Ocarina of Time can be seen in a photo at Hena's fishing hole. Hena thinks she is related but she "can't exactly PROVE it." She also scratches like the fisherman, further linking them together.
It is possible that fire arrows were originally intended to be in Twilight Princess. Fire arrows can be found in the game's data. Though they can only be obtained with a cheat device and they do not function.
Twilight Princess is one of the few Zelda games that does not have a magic meter. As such, there is no need for Green Chu Jelly, which is an item used to refill magic in other Zelda games. However, in the Wii version, it is possible to obtain Green Chu Jelly through normal means. But it is only possible once, in the "Cave of Ordeals", room 19. Carefully kill all of the purple Chus and let a Blue Chu and and Yellow Chu merge. Kill it and then scoop up the remains with a bottle. Link will now be holding a bottle of Green Chu Jelly. It has no text, description or effect whatsoever. However, performing this trick in the GameCube version produces a Purple Chu instead.
Originally, the magic meter was planned to be in the game, and can even be seen on one of the screenshots on the back of the box. Unused text left in the game reveals Link would need magic to transform into his wolf form.
On your way to the Forest Temple, you come across an armored skeletal warrior known as the Hero's Shade. He was a famed swordsman in Hyrule, but died with eternal regret of never having passed on his knowledge in the art of the sword. According to the Hyrule Historia, the Hero's Shade is the spiritual manifestation of the Hero of Time, the Link from Ocarina of Time and Majora's Mask.
There are some The Wind Waker leftovers in the game. These are the Wind Waker item itself, Bomb Flowers and some other items. The file 'itemmdl.arc' contains models of 21 items from The Legend of Zelda: The Wind Waker which suggests Twilight Princess uses The Wind Waker's engine.
Madame Fanadi, the fortune teller says strange words while looking into the future. When you reverse her gibberish, you get coherent sentences. If you ask about love she says, "Wait... loading takes awhile." If you ask her about your career she says, "What am I talking about?"
The 7th dungeon of Twilight Princess, "City in the Sky", is speculated to be based on a painting called "Another World" by M.C. Escher. The creatures, seen on the walls in the painting resemble the Oocca from the game. In the Twilight Princess dungeon, the Oocca are found running on the walls and floor.
According to Shigeru Miyamoto, once Nintendo had finished developing Twilight Princess, the team decided to have fun with the game and put Miis across Hyrule. It was their way of relaxing once the project was done.
Link made his first right-handed appearance in Twilight Princess for Wii. Up through Twilight Princess for Gamecube, Link had traditionally been left-handed but with the introduction of motion controls, director Eiji Aonuma decided to make him right-handed so it would be more comfortable to "swing" the sword with your right hand (which is how most people were playing). Instead of re-doing Link's model though, the Wii version of the game was simply flipped horizontally, reversing the positions of everything from east to west.