Interestingly, Gog and Magog exist also for Muslims under the name Jouj and Majouj. They are kept prisoners in the mountains by a wall which they try to demolish and which is rebuilt every day by Allah. They are supposed to escape at the end of times and rampage all over the world...  

"Dieu se rit des hommes qui se plaignent des conséquences alors qu'ils en chérissent les causes" Jacques-Bénigne Bossuet