Alucard

A Sdrawkcab Name commonly used by vampires that is definitely a Name To Run Away From Really Fast. It is also something of a Shout-Out to arguably the most famous vampire of all time. Sometimes this is just used as an alias, though sometimes the vampire using the alias actually turns out to be Dracula himself. Even more commonly, the vampire in question turns out to be Dracula's son, though it's just as likely it's just their last name or a pseudonym.

Compare contrast Louis Cypher where other dark creatures use similarly witty aliases and Hugh Mann where the creature posing as human also has a Paper-Thin Disguise. Related to Most Definitely Not a Villain.

Examples of Alucard include:

Anime and Manga

Hellsing's protagonist. He's the original Dracula. Him taking the name of Alucard is said to be a name given to him by a former Hellsing leader, specificly Arthur Hellsing, Integra's father.
The protagonist of Vampire Hunter D is named Alucard, and he's Dracula's son.
The hero of Master Mosquiton is Alucard Von Mosquiton.
There is an Alucard present in Rosario + Vampire, though he is a massive, tentacled monstrosity that used to be a vampire before his immense power and hatred turned him into what he is now.

Comic Books

The bizarre Dell Comics superhero version of Dracula used "Aloyisius Ulysses Card" as his secret identity.

Film

The original use of "Alucard" as a vampire's alias was in the 1943 film Son of Dracula, starring Lon Chaney, Jr.
In Hammer Production Dracula A.D. 1972 (1972), Dracula's minion is called Johnny Alucard. Dr. Van Helsing (Peter Cushing) notices the anagram only by writing it and drawing lines.
In The Monster Squad, a kid sees Alucard's name on a post-it note on his parents' refrigerator and plays with the letters until he gets Dracula.
In Santo En El Tesoro De Dracula, the count's reputation precedes him even in 19th century Mexico, so he introduces himself as "El Conde Alucard."

Literature

In Dracula, Go Home by Kin Platt, the villain uses several aliases that are turn out to be anagrams of Dracula, including Alucard.
The Last Vampire by Willis Hall has a Friendly Neighbourhood Vampire descendant of Dracula who goes by "Count Alucard".

Live Action TV

In the Dracula TV series, Dracula went by the name of Alexander Lucard.
A vampire named "Alucard" also shows up on Wizards of Waverly Place.

Music

Progressive Rock band Gentle Giant recorded a song entitled "Alucard", with cryptic lyrics that presumably refer to Dracula.
Tech N9ne has a track called "Alucard" on his Seepage EP. The track is a Boastful Rap detailing exactly why Tech has managed to outlast other rappers, likening his staying power as an artist to a vampire's immortality. The rap ends with Tech shouting "A-L-U-C-A-R-D/Read it backwards!"

Video Games

The protagonist of Castlevania: Symphony of the Night, who first appeared in Castlevania III: Dracula's Curse. His real name is Adrian Fahrenheits Tepes, and "Alucard" is an alias he took up to show that he stood opposed to his father.
There's a vampire named "Alucard" in the top-down shooter Gunbird II...
There is a text adventure game for the ZX Spectrum called Merlock the Mede: The Ashes of Alucard.
BlazBlue brings us Rachel Alucard, a vampiric Elegant Gothic Lolita who has only ever bitten one person.
Played with in the Fan Remake of King's Quest II, where a vampiric count is called Caldaur.

Web Comics

Occurs in The Adventures of Dr. McNinja with the real Dracula (although Doc notes that Ben Franklin's a moron to fall for that name).
In the webcomic Eerie Cuties, teen vampire Layla Delacroix has the middle name Alucardia.

Western Animation

In the animated Batman movie The Batman vs. Dracula, Dracula uses the false identity of "Mr. Alucard, anthropologist". It doesn't take that long for Bruce Wayne to see through this not-too-subtle disguise... via a hackneyed 'write name on object and look at it in the mirror' scene. "World's Greatest Detective" my ass.