Hellsing Ultimate (OAV)

The name Hellsing is derived from Abraham Van Helsing, and it has been indicated that the series takes place in the same continuity as the novel Dracula.

Alucard is Dracula spelled backwards.

The Major ends the third episode by singing the first few lines of "Tough Boy," the theme song from the second Hokuto no Ken TV series. The second line, "kono ikareta jidai e youkoso," means the same thing as the first one, "Welcome to this crazy time."

In the 1st episode, at approximately 44:50 minutes, one of the blades of Father Alexander Anderson stuck in the ground, has the sharp edge on the opposite side (sharp side is on equal lining with the hilt, as on the other blades the sharp side is on the opposite side)

In the 1st episode, at about 46:58, Integra refers to Alucard as "..a man who once was called 'count' ", implying the Alucard may have actually been Count Dracula (his name backwards).

The bodies that Alucard throws out of the hotel in Rio de Janeiro onto the sharp flagpoles are likely a reference to the historical Vlad the Impaler (aka Vlad Tepes, Vlad Dracul, or Dracula = Alucard) and his favorite chosen method for punishing others. (The most famous portrait of Vlad Dracul is used in the TV series to show his erstwhile appearance, clearly linking the two.)

At 16 minutes into Episode 2, Luke Valentine makes short work of several Hellsing soldiers while in front of a mirror, which does not reflect his image. Along with the Seras' mirror sight gag from Episode 1, this suggests that since Seras Victoria is still a fledgling, she needs to drink human blood to become a full Vampire with all the established common traits in Dracula lore.

In the beginning of episode 5, we see a scruffy character talking to Alucard, which is apparently Bruce Willis, also hinting some of his movies: Die Hard, Armagedon, The Sixth Sense and The Fifth Element.

In the ending credits of Episode 6, Seras Victoria complains to Mr. Walters of sexual harassment. What she is complaining about is the military cadence that the Wild Geese were chanting while running, which is a very obvious homage to Gunnery Sergeant Hartman's cadence in the movie Full Metal Jacket.

Seras Victoria's signature weapon is called a Harkonnen, after the main villain from the 1984 film Dune.

It took 6 years for this OVA's production to be finish.

In episode 2 Jan Valentine kills guards that are surrounding him saying "Up,Up, Down, Down, Left, Right, Left, Right" He then says "I'm cheating and I'm invincible." This is very likely a reference to The Konami Code (which starts with those buttons) used in many games made by Konami to enable a cheat, such as giving a player 30 lives in Contra.