"...restores you to full fitness, enabling you to pursue the leisure activity of your own choice during an hour that would otherwise have been devoted to unprofitable boredom.”
-- Fred Weasley (OP6)
"...they're not technically doing anything wrong. ...They're quite within their rights to eat the foul things themselves and I can't find a rule that says the other idiots aren't entitled to buy them, not unless they're proven to be dangerous in some way and it doesn't look as though they are."
-- Hermione Granger (OP17)
One of the range of sweets found in a Skiving Snackbox. Each end of the sweet is colour-coded, so that one end causes the eater to vomit and the other cancels the effect. Fred and George had trouble with the prototype until they got the effect balanced so that the vomiting was severe but not so severe that the cancelling end couldn’t be swallowed.
Hermione gave one to Reg Cattermole in order to send him to St.Mungo's while Ron impersonated him to infiltrate the Ministry. (DH12) She had packed several Weasley's Wizard Wheezes in her beaded handbag.