Recently, a dataminer uncovered that there isn't just one kind of Shiny in Pokémon Sword & Shield, but two - star and square.
While some fans are into Pokémon games for the adventure, others are there for the competitive aspect. There are also players who try to collect all of Shiny Pokémon within the games. Known as the Shiny Hunters, these players dedicate hours of their time hunting down every single Shiny Pokémon each game has to offer.
Though Pokémon Sword & Shield have plenty of Shiny Pokémon to entice Shiny Hunters, a recent dataminer has revealed that there are other types of Shiny Pokémon that players may be lucky enough to encounter (depending on the method).
As players who are currently enjoying the newest Pokémon already know, if one is lucky enough to encounter a Shiny Pokémon in the wild, it will have a square sparkle effect as well as a different color palette. If one manages to get a Shiny Pokémon from an egg hatch, it will have a star sparkle effect as well as have a different palette color. However, as it turns out, it's possible to have the opposite sparkle effect, though it's very rare and can take an extremely large amount of time to achieve.
The information comes from the Pokémon Sword & Shield subReddit, where a user briefly explained the two types of Shiny Pokémon players may encounter and the way those Shiny Pokémon can be encountered. Simply put, a wild encounter will have the square sparkle effect (the effect itself has a 1 in 65536 chance of happening), while any other way (primarily egg hatching) will have the star sparkle effect. It is very possible for the effects to be switched, though, as revealed by a dataminer's tweet.
If Shiny Hunters were to go by this newly-uncovered information, that would mean that there are theoretically two types of Shiny Pokémon for them to find, thus essentially doubling their collection (square sparkle effect and star sparkle effect). In other words, it's certainly within the realm of possibility to get a square sparkle Shiny starter Pokémon via breeding, although it'll be much rarer compared to getting a Shiny starter Pokémon with the star sparkle effect.