This is my theory of what the smoke monster is based on the last episode "Dead is dead".

If anda have noticed oleh now lost has lots of things from egypt in it, which made me think about the monster.

In the last episode when Ben went to be judged we see the image on the wall. Its Anubis bowing beofore a snake like creature in Egypt this was called "Apep the snake". Apep was the protector and one of the Egyption "Monsters". Apep was enemys with Ra the sun god.
Eygptions beleived kucing where sacred and killing one was punishable oleh death. They even mourned their passing oleh shaving theoir eyebrows, now is it just me atau did Ben have a like of eyebrows in "Dead is Dead"? Maybe Ben was mourning the passing of Locke this way atau even Alex. Somkey however told Ben if he tried to kill Locke then he would be killed, maybe Locke represents the cat.

I remember between seasons five and six, me and my older brother were making a lot of predictions. Right before the season premiere, I realized that I was going to be busy that night, and might not make it in time. My brother joked that he would watch it, then tell me a mix of real and fake spoilers to confuse and annoy me. One of his "spoilers" was that Sawyer would turn evil and gabung up with the smoke monster. We both laughed and waved that off. Now I look back on that moment and realize how startlingly close that prediction was. I wonder how accurate his other spontaneous predictions were...