There are fan fictions where Beavis and Butthead accidentally become heroes. Maybe they stumble upon a crime in progress. But instead of handling it in a normal way, they do things like using their stupidity to outwit the criminals. For instance, they might start doing really dumb things that confuse the bad guys so much that the police are able to catch them easily.
One interesting story could be about Beavis and Butthead getting involved in a school play in a very comical way. They misinterpret their roles and end up creating chaos on stage. Another could be their adventure in trying to start a band but having no idea how to actually play music, just making a lot of noise instead.
Well, in some fan fiction, Beavis and Butthead might find themselves in a time - travel scenario. They could end up in the future and be completely baffled by all the advanced technology. For example, they might mistake a holographic display for a real object and try to interact with it in their usual clueless way. This would lead to a series of really funny situations.