Now That's A Stretch is the second part of the 19th episode of season 2 in Dexter's Laboratory. It first aired on November 19th, 1997. In this episode, Dexter combines himself with bubblegum to combat his short stature.
The sound of the chewing gum stretching seems to have been created using the same instrument as the opening guitar riff from Looney Tunes, a steel guitar.
At one point, the staircase was on the left side when Dexter stretched his arms to the kitchen to make a sandwich. When Dee Dee went downstairs to confront Dexter later in the episode, the staircase was seen on the opposite side. (cartoon logic)