|"Johnny's New Baby Sisters"|
|Season 4, Episode 40a|
|United States Airdate:||November 9, 2009|
|Canada Airdate:||September 10, 2009|
"Johnny X: The Final Ending"
Susan and Mary purposely turn themselves into babies while their parents are out because Gil is the babysitter. Johnny has to keep them safe from him, as Gil is irresponsible; this, unfortunately, interferes with a party he and Dukey had been planning.
- This is the first episode of Season 4.