If you quickly Google it: Wikipedia says Balrog, and some Moria Wiki says Barlog.
If you open the book in the translation by N.V. Grigorieva, V.I. Grushetsky, it says Barlog (as in the Moria Wiki). Without translating the text, I don't feel like looking for it)
Added 7 minutes later
I read that in Tolkien's original, it's Balrog, and in the translation, it's supposedly correctly Barlog, I don't know why.
Sybreed – A.E.O.N
the beginning is really cool. But it's not very good after that.