From science to science fiction, there are a lot of theories about what "Ole' Smokey" on "Lost" really is.

Here's some of the more popular theories right now:

1.  Cerberus:  From Greek and Roman mythology, he is the three-headed dog who guarded the entrance to Hades.  Smokey was described by Rousseau as a security system in Season One of the show.

2.  The Man in Black.  We were introduced to Jacob's mysterious foe in the Season Five finale.  Is the Smoke Monster really The Man in Black in a different form?  Throughout Season Five, we have seen and heard Smokey, but never when Locke is around.  In one particular episode, Locke conveniently disappears and the Smoke Monster appears.

3.  The Incident.  Is Smokey related to the "pocket of energy" that was released when the bomb went off?  Smokey does have a kind of "metallic, grinding" sound similar to some of the drilling equipment around the Swan station.

What's Your Theory?

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