The Dragon: The Beast from the Sea, a seven-headed, ten-horned monstrosity who runs the governments of Earth for the Dragon, as it is the Dragon who has given him power. When people say "The Antichrist," this is usually who they mean. Funnily enough, the Great Red Dragon is not The Dragon.
The Evil Genius: The Beast from the Land, apparently an Evil Sorcerer type, who performs miracles to fool people into following the first Beast.
The Brute: Abbadon/Apolyon, commander of the locust-demons that escape from the Abyss before the others even turn up.
The Dark Chick: The Mother of Harlots, at least assuming she's supposed to be a person and not a metaphorically-described place.