This is Tetra◊ as depicted in her prerelease artwork for The Legend of Zelda: The Wind Waker. Even though it was not outright stated, this design seem to indicate that she was originally meant to be an inhabitant of Windfall island, rather than a pirate. It is also questionable if she was already meant to be Princess Zelda in this stage of development.
Link in The Wind Waker was supposed to be a teenager◊ along the lines of Ocarina of Time's second half, Twilight Princess, or Skyward Sword once.
Screenshots of beta The Legend of Zelda: Ocarina of Time showed that the game went through plenty of changes. Originally, there were two extra dungeons - Wind and Ice - which were scrapped (the ice temple was turned into the Ice Caverns and the Wind Temple was reused in The Legend of Zelda: The Wind Waker). Screenshots show Link with the Medallions equipped to the C buttons, indicating that they were at one point designed to actually serve as weapons. A screenshot of octoroks showed that they were originally designed to look much more like their 2D versions (like largeish tick-things on the ground, rather than being aquatic like their namesake animals). Finally, there's the infamous picture of Link finding the Triforce in a cave, which is a pretty good indicator that at one point the player could find the Triforce but it was eventually removed. Not that that's stopped people from still looking…
The 64DD expansion to The Legend of Zelda: Ocarina of Time. Some commentators wonder if Master Quest really represents what the original intention was. An expanded overworld? New dungeons?
Master Quest is not the original Ura Zelda. In an old copy of Wikipedia which refers to a dead link, Ura Zelda would've had new dungeons (possibly the wind/ice dungeon,) new items, new attacks, magic spells, and custom masks created via Mario Artist: Talent Studio and the Game Boy Camera.
Majora's Mask's origins as another 64DD expansion to OoT called Zelda Gaiden, and even OoT itself's origins as a 64DD launch title heavily reliant on rewritability for much-hyped persistent world features.
The Wind Temple in Ocarina of Time was changed to the Forest Temple. Saria was supposed to have less of a role in the game, or possibly a different role, since she didn't teach you any songs. Fado◊ was also supposed to be a sage, the wind sage specifically, but her role was replaced by Saria and she was given an almost insignificant role. Remnants of this and the abovementioned scrapped ice dungeon can be seen in Ganondorf's Castle; the forest segment heavily revolves around wind puzzles, while the water segment involves a Frictionless IceBlock Puzzle.
Link's iconic Sword Beam attack from his previous installments was going to be in the game as well, but it was scrapped early on. The concept is revisited in Majora's Mask where Link can use his magic to shoot sword beams while wearing the Fierce Deity Mask.
Actually, Ocarina of Time was itself originally supposed to be released on the 64DD as its Killer App. It was moved to cartridge once it became clear that the 64DD would never see a US release.
There was intended to be Dating Sim elements to the game (hence why the cast is majority female).
The Wind Waker had the last two planned dungeons (prior to the final one) scrapped due to time constraints and replaced with the controversial Triforce Fetch Quest. The number of dungeons clocked at seven and not nine as intended.
The game originally had a different theme for the Twilight Realm, being in black and white rather than overcontrasted (the final version).
The game was going to have Gorons piled together to make a giant-sized golem. They were Dummied Out.
Sheik (Zelda's disguise from OoT) was originally going to return in this game, but was scrapped for unknown reasons. This also resulted in a Development Gag in Super Smash Bros. Brawl where Sheik's return in that game as one of Zelda's abilities was actually based on this abandoned concept. Although Hyrule Historia suggests that the original artists intentionally left behind a leftover TP-esque Sheik design for Brawl.
The game was also supposed to use a magic system similar to the ones used in the previous Zelda games and many preview screenshots and trailers showed a magic meter. During development, Nintendo scrapped the concept of magic, but forgot to cut out the green Chu Chu. Red ones could be used as a red potion when killed and blue ones used as a blue potion. Green Chu Chus would have been used like a green potion to restore magic, but since magic does not exist in the game, drinking a green Chu Chu simply does nothing. Likewise, the screenshots shown at the back of the game's box shows the magic meter, despite the fact that the game does not use a magic system.
This article goes in-depth into many of the differences. A major difference is that Link was supposed to interact with animals much more.
Ilia had many designs, one of which had dark hair and a Navi tattoo on her forehead. Midna had at least a dozen◊ prototypical designs before we got our final Midna.
The game was originally going to have the cel-shaded graphic style as 'The Wind Waker'' until the developers saw how that game's sales were poor because of the graphic style.
A variantion on the above: early screenshots showed the Twil (and only the Twil) as cel-shaded shadow beings. Rather than an insect on his head, the monkey boss in the first dungeon had some form of hat.
Early on in development, the game used standard button controls for swordplay. As Wii MotionPlus came into play, motion controls were added in.
Switching items involved twisting your wrist rather than pointing in a certain direction.
The character designs were also going to be very different. Ghirahim, for example (CAREFUL: spoilers), went through a load of them, both humanoid and much more demonic. It seems Impa was also at one point imagined as a child◊ instead of a young woman.
Sheik originally had light skin, blue eyes, and a slightly different hairstyle. Her design was probably changed to make it less obvious who she was.
According to concept art, Link in The Legend of Zelda and The Adventure of Link was meant to be a blond instead of the brunette we know of. In contrast A Link to the Past's Link was meant to be a brunette instead of a dirty blond, and looked more like Adventure Link.
According to an interview given by Miyamoto to a French site, the Triforce fragments were originally computer chips and Link was supposed to travel between medieval and futuristic time periods. The name "Link" was not originally supposed to symbolize the link betwen the player and the character, but the link between the time periods.
Some evidence exists that suggests A Link To The Past was supposed to reuse the futuristic idea. There's this very early concept art◊ of Zelda in a scifi get up. This has led some to speculate the Light World/Dark World mechanic was originally going to be a futuristic/medieval world mechanic, as intended in the original game. Why this idea was scrapped twice and never revisited again in Zelda is unknown, though this is probably the inspiration for the time travel mechanic in later entries.
Zelda 3, planned as a Famicom game, was originally going to be an RPG featuring a party system of multiple playable characters, each with their own stories, such as a fairy party member instead of just Link, according to this interview. This design was scrapped for unknown reasons.
Imagi, the studio behind the 2007 TMNT and the 2009 Astro Boy films, apparently wanted to try their hand at an adaptation. It never got past the initial pitch.
Early concept art for Ocarina of Time◊ show the Zora as looking more malicious, Navi not being her normal blue self but resembling the older fairies, and a very early version of Sheik with blue hair and no mask.
Link's hair◊ in Ocarina of Time originally had bangs similar to ALTTP's Link. Similarly that Link originally◊ looked much more like the NES Link.
Characters in Spirit Tracks went, like all Zelda characters before them, through a truckload of different designs. Byrne in particular ran the whole gamut of ranges: from a small, elderly henchman to a wild gentleman, a Dumb Muscle brute, and a mole, all the way up to the badass warrior of the final game. The Final Boss was also envisioned as humanoid, rather than four-legged, and concept images of him crying out in agony after his defeat (CAREFUL: spoilers and mild Nightmare Fuel) were left scrapped, possibly to avoid a feeling of Alas, Poor Villain.
Ocarina of Time 3D was going to have fully orchestrated background music at one point in development, as Star Fox 64 3D later would, but this was vetoed in favor of a straight remaster. One new piece of music did end up in the game, however, as a second end credits theme.
Link's Awakening was planned to have a two-player mode which would work similarly to the later Four Swords and Tri Force Heroes games, including a boss that required one player to throw their partner on top of it, where they could pound a stake with a hammer (another feature not found in the final game). The storyboard (seen in Hyrule Historia) that illustrated this has a note indicating that they couldn't figure out how this boss would work with only one player, so when the two-player mode was cut, the boss went with it. Another storyboard indicates that the Southern Face Shrine was originally going to include a pillar that the player had to ram with the Pegasus Boots to get the key- the pillar would then collapse, revealing the inscription seen in the final game.
The Legend of Zelda: Tri Force Heroes was originally going to have the ability to fuse two players together with the characters only being able to move if both players agreed on the direction in which to travel. It was scrapped after it was decided it would make the game too hard.
The Legend of Zelda: Breath of the Wild had a few very different ideas preceding it; one involving Link fighting against an Alien Invasion, and another involving a modern-day-style Link with a motorcycle and electric guitar in addition to his Master Sword. Likewise, there were plans to have NPCs that were tiny and could be visited if Link shrunk down to their size, similar to the Picori in The Legend of Zelda: The Minish Cap. It was ultimately scrapped since it didn't fit in with the other ideas and designs. When the game was shown at E3 2015, there was a magic meter on the screen. The magic meter was scrapped probably due to the abilities the devs made for Link's Sheikah Slate. Likewise, the developers planned for the Hookshot and Beetle to be abilities Link could use with the Sheikah Slate, but they were scrapped.
Ganon in the The Legend of Zelda was originally going to have a vampire motif, which would explain why he shields his face from the light when you encounter him and why he dies to the Silver Arrows.
Series creator Shigeru Miyamoto revealed in 2016 that Nintendo had shown interest in a Zelda spin-off starring Sheik. Whether it would take place before or after the events of Ocarina of Time has never been discussed as no gameplay prototypes or ideas were ever developed. There is still a desire to make it a reality though.