In Revelation 6: 1-8 John describes four horsemen who look hideous. These four men ride horses that are white, red, black, and pale.

The white horse probably represents conquest or the Antichrist.
The red horse represents war.
The black horse represents famine,
and the pale horse represents death.

Some Christians believe that these four horsemen represent the evil that has been in the world since the beginning of time. Others believe that the horsemen represent wars, famines, and death that will be released during the start of the Tribulation.

   "As I watched, the Lamb broke the first seal and began to unroll the scroll. Then one of the four Living Beings, with a voice that sounded like thunder, said. "Come!"

I looked, and there in front of me was a white horse. Its rider carried a bow, and a crown was placed upon his head; he rode out to conquer in many battles and win the war.

Then he unrolled the scroll to the second seal, and broke it open too. And I heard the second Living Being say, "Come!"

This time a red horse rode out. Its rider was given a long sword and the authority to banish peace and bring anarchy to the earth; war and killing broke out everywhere.

When he had broken the third seal, I heard the third Living Being say. "Come!"

And I saw a black horse, with its rider holding a pair of balances in his hand. And a voice from among the four Living Beings said, "A loaf of bread for $20, or three pounds of barley flour, but there is no olive oil or wine."

And when the fourth seal was broken. I heard the fourth Living Being say, "Come!"

And now I saw a pale horse, and its rider's name was Death. And there followed after him another horse whose rider's name was Hell. They were given control of one-fourth of the earth, to kill with war and famine and disease and wild animals."

Revelation 6: 1-8