The newest addition to Pokémon Sword & Shield is Sirfetch'd, which is a Fighting-type evolution of Farfetch'd that fights with a giant leek sword and a shield made of leaves. Farfetch'd is one of the original 151 Pokémon from Pokémon Red & Blue, yet it is weak in terms of its combat prowess, especially as there is an abundance of Normal/Flying-type Pokémon for it to compete with.
The official Pokémon Sword & Shield website recently uploaded a glitchy page that hinted at a new Pokémon, which many fans suspected was either an evolution or Galarian version of Farfetch'd, known as Sirfetch'd. The reason the fans knew this was due to a leak on 4chan that was filled with legitimate information, including the reveal of Sirfetch'd. The recent trailers for Pokémon Sword & Shield revealed that established Pokémon could have different forms in the Galar region, so the Sirfetch'd leak seemed plausible.
The mystery has finally been answered with a video on the official YouTube channel for the Pokémon series that officially revealed Sirfetch'd to the world. Sirfetch'd is the evolved form of Farfetch'd, whose feathers have turned bright white and wields a giant sharpened leek in battle, while also using a shield that is made from large leaves. Sirfetch'd will be a Pokémon Sword exclusive, like Bea the Gym Leader and Deino & Jangmo-o, though it can be traded to Pokémon Shield. The trailer says that Sirfetch'd is a Fighting-type Pokémon that possesses the Steadfast Ability, which increases the user's Speed stat whenever they have flinched in battle.
The official Pokémon Sword & Shield page on Pokémon.com claims that Sirfetch'd has a unique attack called Meteor Assault, where it uses its leek as a lance to strike a powerful blow that leaves it defenseless during the next turn. The website also claims that Sirfetch'd are known for their nobility and fairness in battle, with one of the most famous paintings in the Galar region depicting a duel between a Sirfetch'd and an Escavalier.
Game Freak had planned to include an evolution for Farfetch'd all the way back in 1997, as was seen in the leaked version of Pokémon Gold & Silver from Space World '97. Farfetch'd originally evolved into a Pokémon called Madame, who also had white feathers and used a much larger leek blade in battle. The similarities end there, as Madame was much bigger and had massive wings, while also sporting black feathers in the shape of a mask. Madame was also a Normal/Flying-type Pokémon and it never used a shield in battle.
Farfetch'd is a Pokémon that has always had a cult following among fans who started with Pokémon Red & Blue, as there was always something likable and silly about a duck who fights with a vegetable in battle. Pokémon Sword & Shield won't have every Pokémon, but the addition of a noble warrior evolution for Farfetch'd is likely to win back many fans who have waited to give Dux and his kin their moment in the spotlight.