The Sea Beast and Earth Beast are two of a kind. Best buds forever. Partners in the fight against all things good. They're also just as ugly as their boss, the Dragon.
• The Sea Beast: He's got seven heads and ten horns, just like the Dragon, but he's sporting crowns on each of his horns. He's also scarlet red and has blasphemous names written all over his body. He kind of looks like a cross between a leopard, a bear, and a lion (13:1-2).
• The Earth Beast: This guy only gets two horns, but he speaks like the Dragon (13:11). His favorite number is 666 (13:18).
These two are the minions of the Dragon. His henchbeasts, if you will. When the Dragon finds out he's been cast down to Earth and wants to cause a ruckus, he raises these two out of the sea and Earth, passes along some of his power, and sends them to work. Like true underlings, they're brought down pretty easily, while the real fight is left for their boss.
So who do these baddies stand for? Well, it's clear that here, like with everything else in Revelation, John wants to take a stab at some real people. Except, he can't come right out and say who they are (that would be illegal and very dangerous). So he takes some inspiration from some beasts mentioned in Daniel 7:1-8 and breaks out secret codes yet again. Bible decoder rings out…
The Sea Beast probably represents the Roman Emperors, specifically Nero, who was the first to persecute Christians and who also claimed that he himself was God (oh, not a good idea). The Sea Beast has seven heads wearing seven crowns, which represents the line of seven emperors of Rome (Nero is actually #7). This is kind of a weird, twisted parody of the Lamb because these emperors are evil kings, not pure, good ones like Jesus and God.
The blasphemous names written all over the Sea Beast's body are probably the titles the emperors took for themselves. Just things like "Son of God" or "Lord and God." Again, not a very good idea, guys (source, p. 1297).
The Earth Beast probably corresponds to the Roman religious authorities. They would have been like priests, but representing the Roman gods (which is a big no-no in the eyes of Christians). The Earth Beast doesn't look so bad. He has two horns, like a normal creature might—but appearances can be deceiving. This guy is out to lure you into a phony faith. That's why he's also known as the False Prophet.
Like the Elect, the Earth Beast gets a mark, but this one indicates his evil status. 666 is the number of the Beast. It's also the value of "Nero Caesar" as written in Hebrew letters (source, p. 1298). Check and mate.
It's really no shock when the two beasts get hurled into the Lake of Fire where they end up burning for all eternity. The Dragon follows about a thousand years later. Sure, these guys had a good run. They controlled the whole Roman Empire and almost wiped out Christianity. But they were really no match for the awesome powers of God and Jesus combined. Better luck next time. Oh wait, there won't be a next time.
Given the time John's writing in and the situation, the beasts probably correspond to Rome, right? Well, sure, but that hasn't stopped people from thinking the beasts were other people. After the Reformation began, Protestants started to pretty quickly think the Pope was the Beast. Anti-Muslim commentators thought the Beast was Muhammad. Seventh Day Adventists think the mark of the Beast is Sunday worship—no surprise, they go to church on Saturday (source).
The lesson here: if there's someone or something you don't like, just tell them they're actually one of the beasts from Revelation. That'll open up a healthy dialogue. (Read: don't actually do this.)
People are pretty obsessed with these guys, that's for sure. The unseen force terrorizing the island in The Lord of the Flies is simply called The Beast, and that book is filled with religious imagery. The number of the Beast—666—is a favorite for artists and writers, too. It's been featured in movies like The Omen, where the number appears as a birthmark on a (very evil) child's head. It's also the combination to the glowing case in Pulp Fiction. Hmmm… what's inside?