Listening to the Fwooper's high pitched, twittering song would drive the listener insane, so each bird must be sold with a Silencing Charm placed on it. The Charm had to be reinforced monthly, and a licence was required to own one of the birds.
Fwooper feathers were used as quills, and they laid patterned eggs.
The four colour varieties of the Fwooper were used to represent the number four, in the runic alphabet.
Uric the Oddball once tried to convince the Wizards' Council that the Fwooper song was actually beneficial to a Wizard's health, and listened to it continuously for three months. His presentation did not go well, when he turned up wearing nothing but a toupee that, on closer examination, was revealed to be a deadbadger.
The Fwooper used to be the mascot of a Harry Potter-based animal rights group called The Protego Foundation (it was previously called The Fwooper Foundation and The Fantastic Beasts foundation) The organisation uses the Harry Potter series to compare how magical creatures (like Pygmy Puffs) in the Wizarding World and creatures in the muggle world (such as cats and dogs) are treated. The ancient rune Fwooper represents the number four, so they focus on four ways animals in the muggle world are used and exploited: animals used for food, used in entertainment, used for clothing, and used for companionship.
*Disclosure: Some of the links above are affiliate links, meaning, at no additional cost to you, Fandom will earn a commission if you click through and make a purchase. Community content is available under CC-BY-SA unless otherwise noted.