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.
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.
The Wind Waker had the last two planned dungeons (prior to the final one) Dummied Out 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.
Early on in development, the game used standard button controls for swordplay. As Wii Motion Plus 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.
According to a recent 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 actually not 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.
A Link To The Past was originally going to have a party system of multiple playable characters, each with their own stories, instead of just Link, according to this interview. This 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.