Ken Raggio explains that the four beasts of Daniel's vision represent end-time powers. The lion is the United Kingdom, the wings of an eagle represent the American colonies, the bear is Russia.
The U.K. and the U.S.A. belong to the black horse. Russia belonged to the red horse until dissolution of the Soviet Union on Christmas Day, 1991, and I propose that the "three ribs in its mouth between its teeth" were the three Baltic republics: Latvia, Estonia and Lithuania.
Since the books of Daniel and Revelation are inspired by the same "word of the Lord," the fourth beast "terrifying and frightening and very powerful" belongs to the red horse because Revelation's similar beast of ten horns has the colour red (Rev. 12:3, 17:3).
Therefore the third beast must belong to the (missing) white horse.
Leopard: The Old Testament depicts the leopard as inhabiting the mountains of Lebanon (Song of Solomon 4:8) ferocious (Jeremiah 5:6) lurking (Hosea 13:7) and swift (Habakkuk 1:8).
Four heads: These are the four "rightly guided caliphs": Abu Bakr as-Siddik, Umar son of al-Jattab, Uthman son of Affan, and Ali son of Abu Talib.
Four wings like those of a bird: The Muslim armies darted back and forth during the era of the four rightly guided caliphs. Islam expanded to the entire Arabian Peninsula, Iraq, Syria, Palestine, Cyprus and Egypt during the first three caliphates. There was no expansion during Ali's but fratricidal slaughter between he and Muawiya the governor of Syria appointed by Uthman.