Mu' meneen Brothers and Sisters,

As Salaam Aleikum wa Rahmatullahi wa Barakatuh. (May Allah's Peace, Mercy and Blessings be upon all of you)

Who is Dajjal,Yajooj,Majooj etc?

In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright. We bear witness that there is no one (no idol,  no person,  no grave, no prophet,  no imam, no dai,  nobody!) worthy of worship but Allah Alone, and we bear witness that Muhammad(saws) is His slave-servant and the seal of His Messengers.

Ref:  Yajooj and Majooj

Yajooj and Majooj are the names of the people of two wild tribes of the north-east Asia, who from the earliest times, had been making inroads on settled empires in Asia and Europe, and ravaging them.   According to the Book of Ezekiel in the Bible (Chapters 38 and 39), they inhabited the territories of Russia and Tubalsek and Moscow.   According to the Israelite history, they were the Seythians who inhabited the land to the north and east of the Black Sea.  

It is related in the Holy Quran that Allah sent a great ruler and believer (Zul-Qarnain), and he built a wall of molten lead to contain the menace of the tribes of Yajooj and Majooj.

Allah Says in the Holy Quran Chapter 18 Surah Kahf verses 94-97:

94      They said: "O Zul-qarnain! the Gog and Magog (people) do great mischief on earth: shall we then render thee tribute in order that thou mightest erect a barrier between us and them?"

95      He said: "(The power) in which my Lord has established me is better (than tribute): help me therefore with strength (and labor): I will erect a strong barrier between you and them:

96      "Bring me blocks of iron." At length when he had filled up the space between the two steep mountain sides he said "Blow (with your bellows)." Then when he had made it (red) as fire he said: "Bring me that I may pour over it molten lead."

97      Thus were they made powerless to scale it or to dig through it.

And it is related in the Holy Quran, that near the end of time,  Yajooj and Majooj will emerge again, and cause  a terrible menace.   This will happen after Prophet Jesus (a.s.) has ridden the world of the menace of the Dajjal.   Then Prophet Jesus (a.s.) and the believers will supplicate Allah Subhanah to help them; and Allah will send a swarm of insects who will kill the full tribe of Yajooj and Majooj.

Allah says in the Holy Quran Chapter 21 Surah Anbiyaa verses 96-97:

96      Until the Gog and Magog (people) are let through (their barrier) and they swiftly swarm from every hill.

97      Then will the True Promise draw nigh (of fulfillment): then behold! the eyes of the Unbelievers will fixedly stare in horror: "Ah! woe to us! we were indeed heedless of this;  nay we truly did wrong!"

Sahih Muslim Hadith 6931     Narrated by Hudhayfah ibn Usayd Ghifari

Allah's Apostle (peace be upon him) came to us all of a sudden as we were (busy in a discussion).  He said: ‘What do you discuss about?’  (the Companions) said: ‘ We are discussing about the Last Hour.’   Thereupon he said:  ‘It will not come until you see ten signs before and (in this connection) he made a mention of the smoke,  Dajjal, the beast,  the rising of the sun from the west,  the descent of Jesus son of Mary (Allah be pleased with him),  The Gog and Magog,  and landslides in three places, one in the east, one in the west and one in Arabia at the end of which fire would burn forth from the Yemen,  and would drive people to the place of their assembly.’

Whatever written of Truth and benefit is only due to Allah’s Assistance and Guidance, and whatever of error is of me.  Allah Alone Knows Best and He is the Only Source of Strength.