Gajira Norimaki, commonly called Gatchan, is an angelic being hatched from an egg deposited on prehistoric Earth by the God of the Galaxy. This placement aimed to halt human technological progress by devouring metal resources, ensuring society remained primitive. Senbei Norimaki later transported the egg to Penguin Village during a time-travel incident, thwarting its original purpose. After hatching, Gatchan initially existed alone but later split into twins via cocoon, becoming the Gatchan Brothers.

Physically, Gatchan resembles a cherubic child with green hair, small flight-capable wings, and antennae firing energy beams called Antenna Beams. The character consumes nearly any substance except rubber, showing a marked preference for metal. Communication relies on a unique language of sounds like "Koo pee pee poo" or "pupipopipi," understood by Arale Norimaki.

Innate abilities include flight anywhere—even space—and scaling surfaces regardless of gravity. The Antenna Beam serves as a weapon, deployed against foes like General Tao. Further powers encompass body manipulation for size shifts or elasticity, self-duplication, space survivability, and stealth mastery. As a gag character, Gatchan wields toon force and reality-warping traits, enabling ghost interactions and immunity to conventional harm.

Within the *Dr. Slump* narrative, Gatchan integrates into the Norimaki family as an adopted sibling to Arale and Turbo, frequently joining Arale's escapades. A pivotal moment occurs when the God of the Galaxy, observing Gatchan's failure to hinder progress due to Senbei's actions, considers Earth's destruction. Witnessing Penguin Village's peaceful coexistence, the deity relents.

In crossovers, both Gatchans aid Arale against *Dragon Ball* characters. They assist against General Blue by dismantling his vehicle and confront General Tao using their Antenna Beam. During the "Future" Trunks Saga in *Dragon Ball Super*, they consume an entire building at a West City science awards ceremony. Gatchan also appears in the one-shot *Dr. Mashirito and Abale-chan*, helping contain a Tech-Tech alien invasion during Arale’s absence.

Notable traits include replicating abilities like the Super Saiyan transformation and leveraging gag-based immortality, surviving complete annihilation. This resilience remains vulnerable to godly destruction powers. The name combines "Gamera" and "Gojira" (Godzilla), leading to the alternate English designation "Gadzilla."