This fruit allows the user to transform in full or hybrid mammoth at will, while in full mammoth form granted by this fruit gives the user a massive frame, significantly increasing Jack's already abnormal size. As an Ancient Zoan, this fruit grants the user greater strength than a normal Zoan, Jack can level buildings with a single swing of his trunk and leave imprints of his feet on the ground just by stepping on it. The hybrid form grants the user a centaur-like body with four mammoth legs, a peculiar case for zoan users, with the upper body of a fish-man with the head, trunk, and tusks of a mammoth. In this form, the user is smaller but still large in size, as well as being faster and capable of wielding weapons for combat.
However, the user is extremely heavy and slow in their full beast form, leaving them unable to dodge high-speed attacks. Otherwise, the user is affected by the standard Devil Fruit weaknesses.
Jack has used this fruit to improve his combat capabilities; he can cause massive destruction with a single attack and bulldoze nearly anything that gets in his way by charging forward. So far, his only displayed attack has been swinging his trunk to damage his opponents and surroundings. In his hybrid form, however, Jack can wield both his shotel blades and use his Devil Fruit powers to augment the power of his swordsmanship in battle.
Due to being a fish-man, Jack can remain conscious and breathe underwater for an indefinite amount of time, although remaining unable to move in the meanwhile.
The initial anime color scheme of Jack's mammoth form.
Jack in his mammoth form in One Piece: Pirate Warriors 4.
In the anime adaptation of the Zou Arc, Jack's mammoth form possessed plain brown fur; this color was also used in the video game One Piece: Pirate Warriors 4. However, when the fruit was used again much later in the Wano Country Arc, the fur color was changed to reddish brown.