Sandrat is a desert traveler marked by a distinctive appearance: a massive black afro obscuring much of his face and eyes. He dresses in a grey shirt beneath a yellow top, bulky green pants, a tattered brown cape, and brown fingerless gloves. He temporarily adopts feline attributes—large ears, paws, and a tail—during Mistral-Bit's trial.

Personality-wise, Sandrat exhibits cunning and deceptive tendencies, often driven by greed for rare cards or monetary rewards. He bribes children with candy concealed in his afro and displays initial cowardice when confronted with failure. Despite this, he occasionally demonstrates compassion toward companions and, inspired by figures like Mei Merryhadda, exhibits moments of bravery and determination against adversaries such as Kiki Beresia. He dislikes being called an "old man."

His background begins with attempting to steal Mei's God-King card through deception, though Tatsumi intercepts him and forces its return. After fleeing, he repeatedly schemes to acquire rare cards, sometimes collaborating with antagonists like General Inui or the protagonists. He later serves as an undercover agent for Inui while traveling with the heroes. When a Soul Spot emerges near his village, he fabricates a story about needing a God-King card for his ailing mother, prompting the heroes to help him obtain The RatTwelveGodKing Mouchuu. He subsequently absconds with the card.

Upon returning to his village, he boasts about Mouchuu but is challenged by the pursuing heroes. Using deceptive tactics, including hiding the card in his afro during battles, he defeats Shunta Mogami, Mei, and Yoku Albatrosa consecutively. After his cheating is exposed, Shunta defeats him in a rematch. The heroes permit him to retain Mouchuu following his pleas, and Shunta and Yoku help restructure his deck to better protect the card.

General Inui later confronts him, reminding him of his undercover obligations and attempting to seize Mouchuu. Mei intervenes, battling Inui to defend Sandrat. Initially skeptical of Mei's abilities, Sandrat witnesses her victory, bolstering his confidence. He resolves to confront Kiki Beresia but falters upon facing her. Encouraged by Mei, he battles Kiki with renewed determination, making a temporary comeback after Mouchuu is destroyed. Ultimately defeated, Kiki confiscates the card. His resolve during this encounter earns unexpected respect.

Later, after acquiring The DragonTwelveGodKing Ourovorius from Shunta, he is challenged by Yoroi. Despite a counterattack using Ourovorius when reduced to one life point, Yoroi defeats him using The DogTwelveGodKing Greedog. Following this loss, he primarily observes battles involving Shunta and Yoku without further direct participation.

In battle, he employs a yellow deck featuring spirits like Kudagitsunen, The Fruitsel Straw-Berry, and The GourmetFairyPrincess Fromage, alongside magics such as Symphonic Burst. After obtaining Ourovorius, he incorporates purple cards like Straw-Puppet and Crystal Break. His battle record includes offscreen losses, deceptive victories against Shunta, Mei, and Yoku, and subsequent defeats against Mei, Kiki, and Yoroi.

He habitually ends phrases with "~chuu" or "~chuu-no," a verbal tic referencing his key spirit, Mouchuu. His name directly alludes to this spirit.