Vipère is a prominent underground golfer notorious as the "Grim Reaper" in illicit golf circles. Her serpentine appearance features long black hair, crimson red eyes, and prominent canine teeth. She typically wears a full-length black Lycra bodysuit that accentuates her physique, using it strategically to distract opponents. A distinctive double snake tattoo near her stomach serves as a covert weapon; during matches, she exposes it to deploy pheromones that disrupt opponents' balance and focus, fueling her winning streak.

Vipère initially employs intimidation and psychological tactics, making suggestive remarks about claiming opponents' bodies as wagers. Her confrontational style is evident facing Eve, representing rival factions in a mafia dispute settled through golf. At Catherine's modular underground course, Vipère attempts to unsettle Eve with pheromones and a bet involving "unforgettable" physical domination. Eve counters by holding her breath during shots, causing Vipère's defeat.

This loss triggers significant development. Vipère questions why her former employer, Nicholas, ordered her assassination afterward, prompting her to reassess her allegiance. Shifting from adversary to ally, she becomes Eve's caddie during a high-stakes duel against Rose Aleon, providing strategic support and course management expertise. Her dynamic with Eve includes a recurring comedic element where Eve persistently calls her "Snake Woman," irritating Vipère, who insists on her proper name.

Following the Nafrece mafia events, Vipère assists Eve and her associates in relocating to Japan. She contributes to establishing The White Hart café alongside Klein and Lily, aiding in securing education for Klein's adopted children. Her ultimate fate remains unresolved after Catherine, the mafia-affiliated course owner, orders assassinations against those involved in her financial losses, including Vipère as Rose's former caddie. Her survival status hangs in the balance.