The Attitude-Reversing Potion is a powerful potion that is able to change a person's attitude and their opposite side if consumed. It is safe with a small drop added to a drink, but should half the bottle be added then the outcome can disastrous; the potion can ware off on its own in time but it antidote can clear the affects much faster.
Role in the series
During the events of "Not in the Mood", Xavier had a bottle of the potion on hand and he gave it to Maximus and Pascal when they wanted to teach Rapunzel, Cassandra and Eugene a lesson. As well as to stop them from fighting. Xavier advised them to give the three a drop each, however, as Pascal was adding it to a jug of lemonade, he was startled by the three still arguing as they entered the kitchen, and accidentally drops the whole bottle into the drink. Once Rapunzel, Eugene and Cassandra drank from it the potion turned them into their opposite sides. Cassandra is overwhelmingly peppy, Eugene no longer feels confident about himself, and Rapunzel is all moody.
Since the affects didn't ware on their own, due to the amount that was consumed by the three, Xavier explained that it will be days before they return back to normal. Unless they take the antidote that is made from the oil from a rare three leafed echo plant, it grows among its two leaf cousin at the top of Mount Saison.