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Biffidus X are stronger versions of Biffidus that appear with Durmite X in the Challenge Node in the game Mario & Luigi: Bowser's Inside Story. One of their attacks consists of the Biffidus X trying to jab Mario or Luigi with its spear. Alternatively, Durmite will eat the Biffidus X and spit it back out at the Bros. They must jump over the flying Biffidus X in order to avoid taking damage.