Tilla Mook with "Vampire Lady" (upper left) and "Vampire's Curse" (bottom right)
"Vampire" (ヴァンパイア Vanpaia) is an archetype of DARK Zombie-Type monsters, except the Warrior "Vampire Hunter". Initially, they were only supported by the manga-only card "Blood Curse" and the manga effect of "Overpowering Eye", but Shadow Specters revealed new "Vampire" support. The Vampire archetype is strongly associated with the Castlevania video game series, one of Konami's best selling franchises.
"Vampire Orchis" and "Vampire Koala" are not "Vampire" cards because they do not have 「ヴァンパイア」 in their Japanese names. Also, their Attributes are EARTH, not DARK, which most Vampire support requires (except "Vampire Vamp").
The archetype is supported by the Field Spell Card "Vampire Kingdom". The card is designed to augment the effects of "Vampire Lord", "Vampire Lady", "Vampire Duke" and "Vampire Grace", but it also works with other effects that mill your opponent such as "Gravekeeper's Servant" and "Iron Chain Dragon". The Trap Card, "Vampire Takeover", is very handy for getting "Kingdom" onto the field, and as well as a free Special Summon from your Graveyard. The main idea behind this strategy is to eliminate key cards in your opponent's Deck and controlling their field.
"Vampires" make an effective Xyz Monster Deck. Using the effects of "Shadow Vampire" and "Vampire Duke" to Special Summon Level 5 DARK "Vampires" (such as each other or "Vampire Lord") and Overlay for the boss of the Deck: "Crimson Knight Vampire Bram". You can also use "Vampire's Curse" and "Vampire Grace" for Rank 6 plays, as well as "Zombie Master" for Rank 4 plays with monsters such as "Vampire Lady" or "Vampire Sorcerer".
"Vampire Sorcerer" is very helpful for both of the Deck's goals. Its first effect allows you to search any DARK "Vampire" monster or any "Vampire" Spell/Trap Card, and its second effect allows you to Normal Summon one "Vampire" monster without Tributing. You can use its first effect to search for "Vampire Kingdom" and its second to Summon "Vampire Lord" or "Vampire Grace" in order to mill your opponent, or you could search for "Shadow Vampire" and use the second effect to Normal Summon it, use the effect "Shadow" to Special Summon "Vampire Lord", and Overlay for a DARK Rank 5.
While "Vampires" are fairly powerful in controlling your opponent's Deck, they can be devastated by their own effects too. Opponents who know that you use "Vampire"s, or during Duels 2 and 3, will be likely to side cards like "Dimension Fortress Weapon", "Skull Invitation", "Breakthrough Skill" or even "Jackpot 7", with the last one being most dangerous due to "Vampire Kingdom"'s effect being compulsory. Decks that utilize the Graveyard as resource are also problem as well, for the same reason. "Lightsworn" Decks in particular can take huge advantage of a "Vampire" player, while Decks such as Zombies and "Infernities" that can construct huge combos out of the Graveyard pose a similar threat.
"Macro Cosmos" and "Dimensional Fissure", as well as "Banisher of the Light" and "Banisher of the Radiance", can easily prove fatal for the "Vampire" strategy, since it relies almost entirely on "Vampire Sorcerer", or at least "Plaguespreader Zombie" or "Mezuki", being in the Graveyard to allow for the Summon of "Vampire Shadow" and "Vampire Duke". Also, cards that negate monster effects on the field, most notably "Skill Drain" (and, by extension, "Soul Drain" for dealing with "Sorcerer") and "Shadow-Imprisoning Mirror", generally prove a complete out against the Deck due to its huge reliance on such.