This is sufficient to make Mohammed an antichrist, but not the Beast of Revelation, who has quite a lengthy job and person description to fulfill, and will not be revealed until the great falling away (apostasy) of 2 Thessalonians 2:3.
For Mohammed, he has fulfilled 1 John 2:22, and is thus an antichrist:
"Who is the liar but he who denies that Jesus is the Christ? This is the Antichrist, he who denies the Father and the Son."
Anyway, onto Mohammed the false prophet and antichrist:
[The portrait of the Prophet of Islam historically projected by Christianity has played an important role in the formation of negative imagery and prejudices about Islam in the collective memory of the Western world.
According to this portrait the church formulated with the influence of religious and political rivalries, Muhammad was not a prophet -- God forbid -- but the Antichrist. Thus, the Prophet of Islam was defined as the Antichrist depicted in the Bible.]
[As a result, according to historic Christianity, the Quran is not divine revelation and Muhammad is not the last prophet. In this portrayal, Islam is seen as dangerous and threatening. Just as barbarians threatened the security of Athens, Muslims threaten the West.]
Full story at "Today's Zaman"