Mashups, when done right, have always been fun. You can take two disparate elements from pop culture, say the audio track from an Indian film trailer or song, and then edit the footage from an American show or film to it. The humour comes from the anachronism. Good examples would be Manjhi and Ironman and Raees and Pablo Escobar.
Recently, a mashup video made of Tom and Jerry episodes and the Kishore Kumar song Aise Na Mujhe Tum Dekho from Darling Darling (1977) went viral. The video, made four years ago by Biswarup Bhattacharjee, has episodes from Tom and Jerry edited to the hit number from the Dev Anand film.