Frederick Duck, better known as Fethry Duck, is an anthropomorphic duck.
Description
The son of Eider Duck and Lulubelle Loon, Fethry Duck is Donald Duck's cousin. He can hardly be better described than by this single word: lunatic. Fethry is unbelievably gullible and naive (easily believing whatever wacky book falls into his long-fingered hands), and also very creative in finding new ways to be obnoxious to the quiet and peaceful. He has been known to engage in fads that will last a week at most before finding a new craze.
Behind the scenes
Fethry was created in 1964 by Dick Kinney and Al Hubbard in their story The Health Nut.