Sirfectch is an avian Pokémon that resembles a white duck, standing no taller than its previous evolution and retaining its yellow beak, brown eyes, and eyebrow-like marking. Its legs and webbed feet are colored yellow, while the three-feather crest on its head and stubby tail are white. Its wings serve as humanoid hands, with the feathers at the end resembling fingers. It carries a massive leek in two parts, wielding the long, sharpened stalk as a lance and using the hard leaves as a shield.
It is said that this evolution was attained by a Farfetch'd who experienced and survived many battles. It is known to be calm and collected, preferring to fight fairly. Due to its noble nature, Sirfetch'd is often chosen as a motif for paintings; one famous painting in the Galar region shows a Sirfetch'd duelling with an Escavalier. The leek it carries is its most prized possession, having maintained it for many years. Once the leek finally withers, Sirfetch'd will retire from battle for good. 
Sirfetch'd appears to be based on a duck and a knight armed with a sword and shield. Like Farfetch'd, it may be inspired by the Japanese saying 「鴨が葱を背負って来る」, literally translating to "a duck comes bearing bunching onions". As a saying, it means "something surprising but convenient". Sirfetch'd may also be based on Sir Lancelot du Lac, one of the members of the Knights of the Round Table. In Arthurian legend, before he revealed his identity to King Arthur, he was known as the "White Knight" for his white armor.
Sirfetch'd may be a combination of sir and far-fetched.
Negigaknight may be a combination of 葱 negi (bunching onion), the prefix giga-, and knight. It may also be a pun on 葱がないと negi ga nai to (must have a bunching onion).
In other languages
From 葱 negi, giga-, knight, and 葱がないと negi ga nai to