"Mr. Whisp shows a lot of promise. If he keeps up the good work, he may well find himself sharing a photo shoot with me one of these days!"
-- Gilderoy Lockhart, author, Magical Me
Kennilworthy Whisp is the author of Quidditch Through the Ages, as well as a number of other Quidditch-related books, including The Wonder of Wigtown Wanderers, He Flew Like a Madman, and Beating the Bludgers. WhizzHard Books published the first edition of his famous book in 1952. Bathilda Bagshot, the famous author of A History of Magic, noted in her promotional blurb about Quidditch Through the Ages, “Kennilworthy Whisp’s painstaking research has uncovered a veritable treasure trove of hitherto unknown facts about the sport of warlocks.”
The date of publication for the first edition of Quidditch Through the Ages is listed in a footnote to the Snidget entry in Fantastic Beasts and Where to Find Them (FB).
"Wisp" = Old English for a small bundle of straw (such as the end of a broom).
Perhaps related to "will-o'-the-wisp", (where wisp relates to the tendril of smoke from a candle which floats away on the air), and therefore "something which deludes or misleads."