Dexter's Laboratory - Look More Carefully for Water!
In the episode where he overloads his Lab and tries to re-energize it using electricity generators, he asks for a river to use his hydro-electric machine. His dad says that they have all been used up. However, in the end of the episode, when he goes outside, there's clearly a river on the right side of the screen which doesn't have anything on it.
TV, eyes, Cartoon Network
on 08-07-2001 and