The fruit enables all parts of the consumer's body to behave like rubber, including their organs. Additionally, falls from great heights and heavy collisions that would kill a normal person end up being non-lethal or even painless, and certain traps and hazards are rendered ineffective considering the user's enhanced flexibility.

The user becomes almost completely immune to blunt damage, including bodily attacks, blunt weapons, bullets, and even cannonballs, all of which will simply bounce off from their skin. Indeed, unlike most other Devil Fruits, the effects of the Gomu Gomu no Mi are always active, making the user's body permanently rubbery. The fruit's major strength, as demonstrated by Luffy, is that the user's body permanently adopts the properties of rubber: their body can stretch, bend, bounce, inflate, and twist much like said substance, even when their power is nullified by way of submergence in water or Seastone exposure.

While its final design has the characteristic Devil Fruit swirls all over it, the fruit was initially drawn without them in the first version of Romance Dawn. Its overall appearance greatly resembles a Yubari King.

The Gomu Gomu no Mi is a violet, spherical shaped fruit, similar to a cantaloupe, with a stem sprouting out of the top, with swirls that go in a curly 'S' like-pattern.

In the VIZ manga, 4Kids and Funimation dubs, it is called the Gum-Gum Fruit, 'gum' being a soft, cohesive substance designed for chewing, with elastic properties, and its original name is called the Human-Human Fruit, Model: Nika.

Nika ( ニカ ?) a word similar to the Romanized Japanese word meaning 'toothy grin,' represents the smiling mythical figure known as 'Sun God' Nika, which the fruit is originally named after.

Hito ( 人 ?) is Japanese for 'person/human (being)'.

Gomu ( ゴム ?) means 'rubber' in Japanese, being borrowed from the Dutch word gom ('gum').

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