My sister was Filling out a personal survey for some theatre thing and the only unfilled question was what fictional character has influenced you the most. She left her laptop unattended and I typed in Beavus and Butthead.
Dreams about pranking someone or altering something they care about can reflect a desire for power or control. It's possible that you have some lingering resentment or negative feelings toward your sister that are manifesting in this dream. Alternatively, the dream could be an expression of an inner desire to disrupt the status quo and inject some humor or irreverence into your own life. If you have any issues communicating with your sister or feel like you're not being heard, this dream may be urging you to find more assertive ways to make your voice heard.