Chickens had feathers. (TV: The Invasion) The word for 'feather' and 'truth' in Hieroglyphs was Ma' at. (PROSE: Set Piece)
The First Doctor once freed John from an octopus' grip by tickling it with a feather. (COMIC: Shark Bait)
The Eighth Doctor referred to the TARDIS as having "a few feathers ruffled." (AUDIO: Blood of the Daleks)
Befitting the style of the time, both Charlotte Pollard and Lucie Miller put feathers in their hair on their trips to the Wild West with the Eighth Doctor. (AUDIO: The 100 Days of the Doctor)