Sabrina: The Animated Series - Season 1 Episode 34 The Hex Files
Overview: Sabrina's class goes to a science observatory. There she and Harvey visit Uncle Quigley who is doing very poorly at his science career. Sabrina and Salem try to boost his confidence by creating aliens for Uncle Quigley to discover. Only one problem she takes these aliens away from Harvey's video game and when the Science observatory finds out they kick Quigley out until some real aliens come that they all see and Quigley, Harvey, Sabrina, and Salem all send them back to their planet. Because of all of this Quigley is finally recognized as a great scientist.