Gajira Norimaki, often called Gatchan, resembles a cherubic being sporting green hair, delicate wings, and antennae, with ambiguous gender traits. Emerging from an egg retrieved by Senbei Norimaki from a prehistoric era, Gatchan joined the Norimaki household and earned its name from Arale, blending "Gamera" and "Gojira" (Godzilla) in homage to her monster obsession. Communicating through unique vocalizations decipherable mainly by Arale, Gatchan possesses a voracious appetite devouring nearly any substance except rubber, with a marked preference for metal.

Its antennae emit defensive energy beams. A pivotal metamorphosis occurs when overconsumption triggers cocoon formation, birthing twin duplicates labeled Gatchan #1 and #2. Subsequent iterations multiply, with later portrayals featuring eight clones.

Gatchan’s celestial roots identify it as an angelic envoy dispatched by Kami-sama, galactic sovereign, to stifle humanity’s technological progress and avert Earth’s ruin. Yet, embracing Penguin Village’s exuberant society convinces Kami-sama to revoke the mission, sparing civilization.

Alternate media iterations include a "Dr. Slump" reboot where Gatchan hatches from machinery with blonde hair. Crossovers into "Dragon Ball" universes showcase Gatchan assisting Arale in confrontations and wielding its Antenna Beam in games like "Dragon Ball Z: Budokai Tenkaichi 3." A live-action G.U. fashion ad features Gatchan soaring alongside allies.

Gatchan’s chronicles involve mischievous escapades with Arale, village shenanigans, and transient transformations—like Senbei’s invention morphing it into a pig. Unwavering innocence and devotion to Arale define its persona, with projections suggesting endless replication cycles while retaining juvenile form.