|Introduced In||The Moth|
When Locke took it upon himself to help Charlie with his heroin addiction, he used the analogy of a moth. He showed Charlie a moth cocoon and stated that the moth was inside struggling to break free, and that he could widen the opening and the moth would be free, but it would be too weak to survive. Locke explained that struggle is nature's way of making us stronger.
After Jack was caught in a cave-in, Charlie tunneled his way into save him, and once in the two were thinking of a way to escape and Charlie notices a moth heading for light at the top of the cave. Later that night, as Charlie receives his heroin back, he burns it in the fire, and a moth flies toward the skies.