Ook
Ook is the main word of Orangutan, the language spoken by orangutans in the fictional Discworld universe of Terry Pratchett — specifically, by the librarian of the Unseen University.Ook (officially "Ook!", with the exclamation mark) is also an esoteric Turing-complete programming language designed for orangutans. The language has 3 keywords — "Ook.", "Ook?", and "Ook!" — which can be combined in eight different ways to form the language's statement repertoire. According to its designers, Ook was meant to be easy for orangutans to learn, and to prevent any mention of the word "monkey".
Note: This language is a parody of brainfuck, from which it borrows its entire command set. It derives its Turing-completeness from this relationship.