From Halopedia, the Halo wiki
Watu Wasio was a human film. It was showing at the Voi Theater in New Mombasa, Kenya when the Covenant invaded Earth in October 2552. The movie's promotional poster seems to suggest that it involves animals as the main characters, including a dog and some form of bird.
The Swahili word "watu" means "people." While "wasio" is not a word, "wa" means "they" applied to people or animals, and "sio" means "are not." Thus, the film's title can be translated as People They Are Not or They are not People.