Ferris Argyle, also known as Felix Argyle by birth is a knight of Lagunica from the popular anime series Re:Zero. Due to the fact that he was born to a noble family, but was clearly a demi human even though both of his parents were human, he was locked in his families basement for the first 10 years of his life, causing severe malnutrition and growth issues in his body, leaving him frail and lithe.

At the age of 10, he was released from his life long prison by a member of another noble family called Crusch, who took Felix in as her personal servant. Felix dedicated his life to serving Crusch, and even though he was weak, he became a knight of the Kingdom and is renowned for being the best healer you can find.

Later on when Crusch became the head of her household, she had to strip her feminimity, leading Felix to adopt it for her and dress in clothing that she finds pleasing.

While there is some debate on the matter, Felix has clarified many times that he is a man in both body and mind, and while he doesn't correct people who mistake him for a girl, he loves being around when people find out the truth about it him.