Future Stan

The actor who plays "Future Stan" appears in the episode My Future Self n' Me.

The False Future
In the supposed future painted by "Future Stan", after touching one marijuana joint, Stan's life spiral down into a self-destructive series of events in which he became hooked on assorted drugs. He eventually ended up being sent to juviniel hal, during which he lost contact with his childhood friends. He would later be released and spend the rest of his life living on the streets, doing assorted and unspeakable things for drugs and booze.

Then one night after falling asleep behind a crack-house, he got got in a time-matrix and was transported back into his own childhood. The Marsh family took him in upon his arrival.

The Truth
In truth, "Future Stan" was nothing more than an profession stage actor associated with Motivation Corp, a company created by ultra-liberals who felt rather than speak honestly with kids about drugs, sex and other vices, parents could instead manipulate them with supposedly dismal futures involving time-travel. Randy and Sharon hired Motivation Corp in the hopes of doing this with Stan. Stan however crew suspicious when he learned that Butters also had a future-version of himelf living with him and his family. After investigating, he and Butters discovered the Motivation Corp connection. Stan attempted to get his parents to tell him the truth, by attempting to cut his hand off, with the belief that if the older "Stan" was truly his future-self, his hand would vanish. Rather than admit their lie, Randy let Stan cut off his hand, and then proceeded to cut off the "Future Stan's" hand. The child Stan however hadn't really done, and Future Stand was left bleeding on the floor. What happened after Randy cut off his hand is unknown, but it's possible he was hospitalized and fired from Motivation Corp.

Trivia

 * The promotional image of Stan's 'future self' (see side image above), is the not the completed model used for the episode. In the episode, Stan's future-self is considerably more over-weight, with long messy brown hair, and heavily lidded eyes. The original version however showed him as being still rather slim, with shorter hair and stubble on his chin.