Fethry is a son of Lulubelle Loon and Eider Duck. His brother is Abner "Whitewater" Duck. Their paternal grandparents are Dabney Duck and Elvira "Grandma Duck" Coot. Their first cousins include Donald Duck, Della Duck and Gladstone Gander. Fethry is a beatnik. He has a rather unorthodox way of viewing and reacting to the world around him.
Since the early 1970s, Fethry has occasionally donned superhero garb and called himself the Red Bat. Occasionally Gloria, Fethry's girlfriend (created by Gerson Luiz Borlotti Texeira), would team-up with the Red Bat as another costumed crime-fighter called the Purple Butterfly (Borboleta Purpurea). Even Fethry's nephew, Biquinho, has donned a costume and called himself Red Bat Junior. Fethry often appears in Uncle Scroooge and Donald Duck tales. In his earliest adventures he supposedly lived in another state (possibly New York or California), and had to visit via airplane or train. However, since 1964 he has resided in an old house definitely in Duckburg. He is also closely associated with the hillbilly Hard Hair Moe and Tabby, Donald's pet cat. Both dislike Fethry very much but Fethry doesn't seem to understand this and is always friendly to them.
He's had his own comic series in Brazil.