Tommy Westphall (St. Elsewhere)

Tommy Westphall is a character in the American hospital series St. Elsewhere.

Autism
Tommy is first confirmed to be autistic in season 2, episode 8 ("All About Eve").

Tommy Westphall universe hypothesis
The final sequence of the final episode of the series indicates that all of the events happened in Tommy's imagination. Many other series are indirectly or directly connected to St. Elsewhere via crossovers and spin-offs, which can be interpreted to mean that all of these series are also part of Tommy's imagination, giving rise to the Tommy Westphall Universe. Depending on how strictly one counts, the Tommy Westphall universe can span more than 500 works of fiction, including The X-Files, Doctor Who and The Wire.