Ewww That's Growth is the first part of the 10th episode in season 2 on Dexter's Laboratory, which aired on September 17, 1998. In this episode, Dexter tries to make himself taller since he is unable to ride a roller coaster with his family.
The episode name is a pun on the exclamation "Ewww, that's gross!"
Dexter gets mail from Mailman Mel, Dad ordered to the family to go on a roller coaster, but Dexter is to short for the roller coaster so he makes himself grow. the episode ends with Dexter riding the roller coaster but being so tall that he hits his head on a tunnel it goes through.