Incognito

Incognito is a masochistic vampire is from "the dark continent," a reference to Africa. Though physically androgynous, he is generally thought to be male. Extremely powerful, he combines dark magic with an enchanted ArmsCor 40 mm grenade launcher that fires spines. Incognito vomits into the launcher's cartridges before loading; and he also is known to have a gatling gun as backup.

During the final plot arc of the series, he summons a snake-like being referred to as Set (presumably the Egyptian god of chaos) and takes it into his body in order to use its power to attack Alucard. Incognito has regenerative powers which seem to be related to the purple stripes and sigils covering his body. It has also been argued that, while Alucard may be inspired by—or is—Count Dracula, Incognito may have been inspired by the vampire Count Orlok, from the 1922 silent movie "Nosferatu: The Vampyre."

Incognito does not appear in the manga and his name comes from the literal definition of the word, incognito. Alucard also states in episode nine that Incognito is an anagram.

(Source: Wikipedia)