Joey, a regular in the comic strip, only appears in 4 episodes in the tv series.

Of course Margaret is in both.

But was Tommy ever featured in the comic strip, or Seymore? (who doesn't come along til season 2).:confused:

I don't think Tommy or Seymour were in the comic strip.
It's funny that Joey is referenced in several episodes after his departure from the series, even into Season 2 ... almost the opposite of how George and Martha were referenced very little after their characters left the show.