Malodorous Fibbian

The Malodorous Fibbian is an item in Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. It is a toxic frog that was created by the Best Fitness Friends, who combine the frog's breath with Skeletone Formula:D to turn it into Malatone Formula:X and then feed it to Morton. This causes him to become hostile to Bowser Jr. and his minions, thus throwing them right onto the ocean of Plack Beach.

Trivia

 * Its name is a play on the prefix "mal-," meaning "bad" and the words "odor" and "amphibian."