Berg Katse originated as a genetically engineered mutant, created when the alien Leader X fused fraternal twins (one male, one female) within the womb to lead the terrorist group Galactor. This fusion granted the ability to shift between male and female forms, causing severe instability during childhood marked by almost yearly involuntary changes. These transformations forced frequent relocations and school transfers until adulthood, when control was achieved, enabling mastery of disguise and subterfuge. In the standard male presentation, Berg Katse wears a distinctive light purple bodysuit and matching mask featuring long, bat-like ears, complemented by a dark purple cape with red lining, red boots, gloves, and a black belt with a shield-shaped buckle. Unmasked, the appearance is androgynous, featuring long dark blond hair, grayish-blue eyes, and notably full lips. Female forms vary in hairstyle (often a bun or ponytail) and attire, though facial features differ across episodes. The OVA redesign replaced the mask's eye lenses with a blue visor, added pointed extensions, and featured a violet-and-red bodysuit under a white overcoat and cape, with lighter blond hair and golden eyes unmasked. A cancelled Imagi film project envisioned Katse solely as a beastly alien male in futuristic armor, removing the gender-shifting aspect. Personality exhibits volatile mood swings, hysterical outbursts, and brutal leadership. Loyalty to Leader X is paramount, manifesting as fear-driven obedience due to severe consequences for failure. Traits include cowardice, mercilessness toward subordinates, and abandoning soldiers during defeats. Female forms display higher intelligence (IQ 280+), enabling complex strategic planning, while male forms possess greater physical strength but diminished intellect and increased arrogance. The OVA portrayal diverged, depicting a calmer, more coldly sadistic and competent figure fully aware of and willingly complicit in Leader X's plan to destroy Earth, contrasting the original series' depiction as a manipulated pawn. Abilities include mastery of disguise, leveraging gender-shifting to infiltrate undetected by humans or technology. Enhanced physical combat skills allow engagements with multiple opponents simultaneously, including the entire Science Ninja Team. Heightened intelligence facilitates rapid adaptation of plans during missions. Katse commands the Bolster, a flying saucer hovercraft capable of evading pursuit by the God Phoenix aircraft. Throughout the original series, Berg Katse directed Galactor's operations against the Science Ninja Team under Leader X's orders. Key developments included growing suspicion about X's motives, particularly regarding the destruction of useful resources like the Mantle Project. The climax revealed Leader X's deception: rather than granting Katse rule over Earth, X planned its annihilation following the loss of his home planet, Selector. Betrayed and despairing, Katse expressed a wish to have lived as two separate humans before committing suicide by leaping into magma. The OVA altered this ending, with Katse fatally stabbed by Ken Washio while asserting Galactor's enduring threat. International adaptations frequently reimagined the character. In *Battle of the Planets*, Katse was renamed Zoltar, depicted as an alien Spectran overlord. The female form was split into multiple characters, including Zoltar's sister Mala and agents S-9, Ms. Ostric, and Hanna. *G-Force: Guardians of Space* retained the Galactor name but presented Katse as an alien entity, with the female form occasionally treated as a separate operative.