Incognito is a major antagonist introduced specifically for the first anime adaptation, serving as a formidable and ancient adversary to the Hellsing Organization. His origins trace back to the "dark continent," a term used to reference Africa, and he is established as a pure, true-born vampire, distinct from the artificial beings created through scientific means. His name, which literally means to operate under a disguised identity, is remarked upon by his nemesis as being an anagram, adding a layer of mystery to his character.

Physically, Incognito possesses a striking and inhuman appearance that sets him apart. He is a lanky figure with purplish-gray skin, an elongated crown and left arm, and highly distinctive eyes where his left one is abnormally large and red, often fixed in a glaring position. His body is adorned with various golden piercings located on his chin, forehead, and chest, and he is often seen wearing a thick gold necklace and cuffs. When he activates his magic, his body becomes covered in purple, glowing sigils and tattoos, most notably one on his forehead that resembles a third eye.

In terms of personality, Incognito is a sadomasochistic entity who lives for chaos, pain, and total destruction. He openly expresses a desire for eternal pain, claiming it as his greatest pleasure, and states that he was born for no other purpose than to bring ruin to everything. He is a cunning and patient tactician, capable of orchestrating elaborate traps and manipulating events to corner his enemies rather than relying solely on brute force. Despite serving a human master who is a traitor within the English Round Table, Incognito largely acts on his own whims, demonstrating a will that is not completely subservient. His own motivations are primarily selfish and hedonistic; while he seems loyal to the Egyptian god Set, he ultimately plans to betray and absorb the deity to steal its power for himself, showcasing his power-hungry and ambitious nature.

Within the story, Incognito functions as the primary force driving the conflict in the anime's second half. He is directly responsible for the creation and proliferation of the FREAK Chips, which turn humans into artificial, impure vampires. He arrives in England to unleash wrath upon the nation, collaborating with a "Judas" figure within the Hellsing Organization's governing Round Table. He commands a small network of followers, including the vampire siblings Jan and Luke Valentine, as well as a turned human named Paul Wilson who serves as his right hand. His key relationship is with his unseen Master, a member of the Round Table whose identity is never revealed but who is discovered and dealt with by Integra Hellsing after the conflict. However, his most significant dynamic is with Alucard, in whom he finds a worthy opponent. The two are established as being on a similar level, both being ancient, original vampires who wield man-made weapons and serve human masters.

Incognito's role in the narrative escalates from a hidden threat to an open one. After a series of manipulations, including turning an entire SAS regiment into his vampire soldiers and framing Hellsing for terrorism, he confronts Alucard directly. In their first major battle, he demonstrates his superior cunning by depleting Alucard's ammunition and using his dark magic to nearly kill the vampire, even turning Alucard's own blessed silver bullets back on him. He then kidnaps Integra Hellsing to use her as a sacrifice for a ritual. In the final arc, he successfully summons the serpentine entity Set, referred to as an Egyptian god of chaos, and absorbs it into his own body to gain its power for a final, destructive battle over London.

Incognito possesses a wide array of remarkable abilities that make him a near-equal to Alucard. He is a master of dark magic, which he uses for offense, defense, and regeneration; the sigils on his body appear to act as a shield and allow him to regenerate from otherwise fatal wounds. His magical techniques include phasing parts of his body out of reality to become temporarily invulnerable to attacks and telekinetically hurling projectiles back at his enemies. Despite being a vampire, he is proficient with high-caliber human weaponry. His primary weapon is a custom 40mm six-shot revolver-type grenade launcher that fires cartridges filled with dark magic spines "cursed by the dark continent." In a grotesque display, he must vomit a set of these magical spines into the cartridge assembly to reload the weapon. He has also been seen wielding a minigun and a heavy machine gun in combat.

Throughout the anime, Incognito undergoes little character change, remaining dedicated to his goal of destruction. However, his role in the plot is defined by his development from a mysterious and behind-the-scenes manipulator to a direct, god-like threat. Notably, he is one of the few characters in the entire series to come close to defeating Alucard, and he is killed only when Alucard, having been forced to remove his power restraints and subsequently use a melted silver cross as a makeshift stake, finally impales him.