This subgenre began with Paolo Cavara's, Gualtiero Jacopetti's, and Franco Prosperi's Mondo Cane, from which the subgenre takes its name and of which subsequent films utilized the word to identify themselves as being in the subgenre. With the English translation of the film's title being A Dog's World, the film was predominantly an exploration of unusual cultural practices in Africa and Asia, such as a cannibal tribe in Africa with ritualistic boar clubbing and a practicing South Pacific cargo cult. Europe and America had their share of weird behavior represented, too, such as inbred Italians and a restaurant in New York where posh patrons dine on insects. For a time subsequent Mondo films would adhere to this premise. In the 80s the films dropped unusual cultural practices as subject-matter and began to focus exclusively on gruesome ways in which people and animals can die, with such films sometimes regarded as being in a sub-subgenre called "Death Films". Another offshoot common in The '60s was documentaries about strippers and other excuses for women to be topless.
More often than not, the legitimacy of these films as documentaries was limited. Rarely did the filmmakers do the research; content was exaggerated and sensationalized in hopes of fulfilling the films' primary purpose of drawing as large a box office return as possible. Though the films would boast of featuring authentic footage, the greater majority of what was in them was in fact staged. The aforementioned death films loved to boast of featuring authentic killings; but it is common knowledge that never, in the history of cinema, has an actual human being been deliberately killed for purposes of film (not counting literal Snuff Films that only exist on the Dark Web). The animal killings, on the other hand...
Sensationalist documentaries existed (thought not in a proper "mondo" format) before Mondo Cane. In fact, one of Thomas Edison's early films was the electrocution of an elephant, making this trope Older Than Television.
Anyways, aside from the aforementioned Mondo Cane, here are some titles belonging to the Mondo subgenre, with English translations in brackets where appropriate:
- Il Mondo di Notte (The World by Night): Gualtiero Jacopetti's documentary about nightclubs made before Mondo Cane. Quite possibly the Ur-Example.
- Addio zio Tom (Goodbye Uncle Tom): Reenactments of the slave trade and American slavery.
- Africa Addio (Farewell Africa): About European colonial powers leaving Africa in a state of chaos. Noteworthy for having the only combat footage taken of the Congo Mercenaries.
- The film was released in the UK in a more or less straight edit and dub, with Farewell Africa as the title. The US version was heavily edited to focus exclusively on scenes of carnage and released as Africa: Blood and Guts. The directors, the aforementioned Jacopetti and Franco Prosperi, were not involved with the US edit and disowned it.
- Banned from Television: showcases footage that's too violent to show on television.
- Faces of Death
- Faces Of Gore
- La Donna nel Mondo (Women of the World): About the role of women in various countries.
- Mondo Cane 2 (A Dog's World 2): Also edited and released as Mondo Pazzo (Insane World).
- Mondo Cane 2000: L'incredibile (A Dog's World 2000: The Incredible): Not an official sequel.
- Mondo Cane Oggi (A Dog's World Today): Not an official sequel.
- Shocking Asia: A compilation of strange and exotic cultural practices from South, East, and Southeast Asia, with a focus on the latter.
- Svezia, inferno e paradiso (Sweden: Heaven and Hell): a largely sensationalized, titillating examination of liberal sexual attitudes in Sweden. Now best known for its soundtrack, from which "Mah Na Mah Na" originated.
- Traces Of Death
- Ultime Grida Dalla Savana (Savage Man, Savage Beast)
- Mr. Mike's Mondo Video: a parody from Saturday Night Live head writer in The '70s, Michael O'Donoghue.
- When Animals Attack!: a live-action TV version of this genre. The FOX network was (in)famous for running these specials in The '90s.
- ''The S From Hell'': a more modern (made in 2010) and more low-budget version of the genre. Unlike others it goes about the Screen Gems logo and the horrible effects it has on society.
A decent list (with mini-reviews) can be found here.