Are Yajuj Majuj part of the human race or are they different creatures? Same question about Dajjal.
There are 2 verses in the Qur'an mentions about Gog Magog.
They said, "O Dhul-Qarnayn, indeed Gog and Magog are [great] corrupters in the land. So may we assign for you an expenditure that you might make between us and them a barrier?" (Surat Al-Kahf 18/94)
Until when [the dam of] Gog and Magog has been opened and they, from every elevation, descend. (Surat Al-'Anbya' 21/96)
We can't say anything about their humanity from these verses, but probably they are humans, because I never heard of a non-human intelligent creature apart from angels and djinns. I assumed that they are intelligent (at least more than animals) because of the corruption they made. They can't be angels because of the angels's nature. They might be djinns or humans.
About Dajjal, there are no verses for him/it. It is a very controversial topic. Some scholars say he is a human, some says he is not a living thing, and some says he is completely made up. Here are some hadith about the topic. Some people believe that Dajjal is not actually a human, but a source of greatest fitnah ever and accuse television, internet etc. Some scholars believe if it was real, it would have mentioned in The Qur'an. And they believe that all the hadith about Dajjal are completely made up.
So, Dajjal is a very controversial topic.
actually I wanted to comment on Kalahari's post, but I can't since my reputation is below 50 ^______^
According to some hadiths they are human. According to some other hadiths, they are not human but some sort of animals which are kept underground and will be released before the arrival of Jesus. It seems that they will mainly attack western lands and Jesus will fight them and drown them in some sea.
according to Al-Nawawi, Yajuj Majuj and Dajjal are a human
Selam Aleykum, Of course none but Allah know what Gog and Magog really are. Coming from an Information technology and electrical engineering background, I would like to present my theory on what Gog and Magog (ref G&M) might be.
As the previous answers have eluded, there was a wall built to keep G&M out but what I found interesting from the standpoint of answering the question is the material this wall was composed of; iron and copper.
If we take iron to be a metaphor for magnetism and copper to symbolize electricity, we combine the two metaphors to symbolize electromagnetism. So with my background, I interpret the Quran as saying there are certain beings that will cause trouble for mankind but they can only come into existence at some time in the future when the electronic or electromagnetic technology to make them possible comes to fruition.
Noah Hariri in his best selling book "A history of the future" talks about a troubling trend where computer algorithms are replacing humans in many sectors of the economy particularly the online economy. Humans are really starting to become obsolete.
So we already see this trend where droids, robots, and software algorithms are taking over. If these droids ever start developing their own consciousness and listen to the whispers of the jinn or sheytan, we can at that threshold say that they are indeed G&M and will take over the earth as they will be much more intelligent and infallible than humans. Then only through Allah's mercy will there come a savior (return of Jesus, Mahdi ) to subdue G&M and bring Sharia to the whole earth.