Green’s Dictionary of Slang

goopher feathers n.

(US) nonsense.

1928		Snooks Friedman [title] Goofer Feathers Blues.
1949		N.Y. Herald Trib. 2 Aug. 12/2: In the process, they made ‘goopher feathers’ — defined by Mack as ‘the fuzz offa peaches’ — a by-word for nonsense, and launched a string of anecdotes that remain as echoes of the ’30s.