Hideo Kojima provided the voiceovers for the Chupacabras in this version.
Many members of the Metal Gear Solid voice cast worked on the voiceovers for the Japanese release.
In addition, the render for Gabriel with the Solid Eye and bandanna has him holding a cigarette, alluding to how Snake in his home series was a well-known smoker. These items are worn by the series protagonist, Solid Snake, in Metal Gear Solid 4: Guns of the Patriots.
Metal Gear Solid: Portable Ops/ Metal Gear Solid: Portable Ops Plus Ironically, Vamp's rival and the game's main protagonist, Raiden, resembles Alucard slightly. Coincidentally, Vamp, like the animated series version of Alucard, is also bisexual. However, he is not a vampire despite his nickname and appearance, as stated by Iroquois Pliskin (Solid Snake), though he nevertheless has vampire-like traits such as a literal thirst for blood, enlarged canines, and most infamously his ability to revive from fatal wounds (later revealed in Metal Gear Solid 4 to be the result of a nanomachine base that regenerates wounds at a rapid rate). He is also Romanian in nationality. One of the antagonists of the game, Vamp, shares the same voice actor in Japan as Alucard in the standard series, Ryōtarō Okiayu.